/*------------------------------------------------------------------------- * * ruleutils.c * Functions to convert stored expressions/querytrees back to * source text * * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/utils/adt/ruleutils.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include #include "access/htup_details.h" #include "access/sysattr.h" #include "catalog/dependency.h" #include "catalog/indexing.h" #include "catalog/pg_aggregate.h" #include "catalog/pg_authid.h" #include "catalog/pg_collation.h" #include "catalog/pg_constraint.h" #include "catalog/pg_depend.h" #include "catalog/pg_language.h" #include "catalog/pg_opclass.h" #include "catalog/pg_operator.h" #include "catalog/pg_proc.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" #include "commands/defrem.h" #include "commands/tablespace.h" #include "executor/spi.h" #include "funcapi.h" #include "mb/pg_wchar.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "optimizer/tlist.h" #include "parser/keywords.h" #include "parser/parse_node.h" #include "parser/parse_agg.h" #include "parser/parse_func.h" #include "parser/parse_oper.h" #include "parser/parser.h" #include "parser/parsetree.h" #include "rewrite/rewriteHandler.h" #include "rewrite/rewriteManip.h" #include "rewrite/rewriteSupport.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/hsearch.h" #include "utils/lsyscache.h" #include "utils/rel.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/tqual.h" #include "utils/typcache.h" #include "utils/xml.h" /* ---------- * Pretty formatting constants * ---------- */ /* Indent counts */ #define PRETTYINDENT_STD 8 #define PRETTYINDENT_JOIN 4 #define PRETTYINDENT_VAR 4 #define PRETTYINDENT_LIMIT 40 /* wrap limit */ /* Pretty flags */ #define PRETTYFLAG_PAREN 1 #define PRETTYFLAG_INDENT 2 /* Default line length for pretty-print wrapping: 0 means wrap always */ #define WRAP_COLUMN_DEFAULT 0 /* macro to test if pretty action needed */ #define PRETTY_PAREN(context) ((context)->prettyFlags & PRETTYFLAG_PAREN) #define PRETTY_INDENT(context) ((context)->prettyFlags & PRETTYFLAG_INDENT) /* ---------- * Local data types * ---------- */ /* Context info needed for invoking a recursive querytree display routine */ typedef struct { StringInfo buf; /* output buffer to append to */ List *namespaces; /* List of deparse_namespace nodes */ List *windowClause; /* Current query level's WINDOW clause */ List *windowTList; /* targetlist for resolving WINDOW clause */ int prettyFlags; /* enabling of pretty-print functions */ int wrapColumn; /* max line length, or -1 for no limit */ int indentLevel; /* current indent level for prettyprint */ bool varprefix; /* TRUE to print prefixes on Vars */ ParseExprKind special_exprkind; /* set only for exprkinds needing * special handling */ } deparse_context; /* * Each level of query context around a subtree needs a level of Var namespace. * A Var having varlevelsup=N refers to the N'th item (counting from 0) in * the current context's namespaces list. * * The rangetable is the list of actual RTEs from the query tree, and the * cte list is the list of actual CTEs. * * rtable_names holds the alias name to be used for each RTE (either a C * string, or NULL for nameless RTEs such as unnamed joins). * rtable_columns holds the column alias names to be used for each RTE. * * In some cases we need to make names of merged JOIN USING columns unique * across the whole query, not only per-RTE. If so, unique_using is TRUE * and using_names is a list of C strings representing names already assigned * to USING columns. * * When deparsing plan trees, there is always just a single item in the * deparse_namespace list (since a plan tree never contains Vars with * varlevelsup > 0). We store the PlanState node that is the immediate * parent of the expression to be deparsed, as well as a list of that * PlanState's ancestors. In addition, we store its outer and inner subplan * state nodes, as well as their plan nodes' targetlists, and the index tlist * if the current plan node might contain INDEX_VAR Vars. (These fields could * be derived on-the-fly from the current PlanState, but it seems notationally * clearer to set them up as separate fields.) */ typedef struct { List *rtable; /* List of RangeTblEntry nodes */ List *rtable_names; /* Parallel list of names for RTEs */ List *rtable_columns; /* Parallel list of deparse_columns structs */ List *ctes; /* List of CommonTableExpr nodes */ /* Workspace for column alias assignment: */ bool unique_using; /* Are we making USING names globally unique */ List *using_names; /* List of assigned names for USING columns */ /* Remaining fields are used only when deparsing a Plan tree: */ PlanState *planstate; /* immediate parent of current expression */ List *ancestors; /* ancestors of planstate */ PlanState *outer_planstate; /* outer subplan state, or NULL if none */ PlanState *inner_planstate; /* inner subplan state, or NULL if none */ List *outer_tlist; /* referent for OUTER_VAR Vars */ List *inner_tlist; /* referent for INNER_VAR Vars */ List *index_tlist; /* referent for INDEX_VAR Vars */ } deparse_namespace; /* * Per-relation data about column alias names. * * Selecting aliases is unreasonably complicated because of the need to dump * rules/views whose underlying tables may have had columns added, deleted, or * renamed since the query was parsed. We must nonetheless print the rule/view * in a form that can be reloaded and will produce the same results as before. * * For each RTE used in the query, we must assign column aliases that are * unique within that RTE. SQL does not require this of the original query, * but due to factors such as *-expansion we need to be able to uniquely * reference every column in a decompiled query. As long as we qualify all * column references, per-RTE uniqueness is sufficient for that. * * However, we can't ensure per-column name uniqueness for unnamed join RTEs, * since they just inherit column names from their input RTEs, and we can't * rename the columns at the join level. Most of the time this isn't an issue * because we don't need to reference the join's output columns as such; we * can reference the input columns instead. That approach can fail for merged * JOIN USING columns, however, so when we have one of those in an unnamed * join, we have to make that column's alias globally unique across the whole * query to ensure it can be referenced unambiguously. * * Another problem is that a JOIN USING clause requires the columns to be * merged to have the same aliases in both input RTEs, and that no other * columns in those RTEs or their children conflict with the USING names. * To handle that, we do USING-column alias assignment in a recursive * traversal of the query's jointree. When descending through a JOIN with * USING, we preassign the USING column names to the child columns, overriding * other rules for column alias assignment. We also mark each RTE with a list * of all USING column names selected for joins containing that RTE, so that * when we assign other columns' aliases later, we can avoid conflicts. * * Another problem is that if a JOIN's input tables have had columns added or * deleted since the query was parsed, we must generate a column alias list * for the join that matches the current set of input columns --- otherwise, a * change in the number of columns in the left input would throw off matching * of aliases to columns of the right input. Thus, positions in the printable * column alias list are not necessarily one-for-one with varattnos of the * JOIN, so we need a separate new_colnames[] array for printing purposes. */ typedef struct { /* * colnames is an array containing column aliases to use for columns that * existed when the query was parsed. Dropped columns have NULL entries. * This array can be directly indexed by varattno to get a Var's name. * * Non-NULL entries are guaranteed unique within the RTE, *except* when * this is for an unnamed JOIN RTE. In that case we merely copy up names * from the two input RTEs. * * During the recursive descent in set_using_names(), forcible assignment * of a child RTE's column name is represented by pre-setting that element * of the child's colnames array. So at that stage, NULL entries in this * array just mean that no name has been preassigned, not necessarily that * the column is dropped. */ int num_cols; /* length of colnames[] array */ char **colnames; /* array of C strings and NULLs */ /* * new_colnames is an array containing column aliases to use for columns * that would exist if the query was re-parsed against the current * definitions of its base tables. This is what to print as the column * alias list for the RTE. This array does not include dropped columns, * but it will include columns added since original parsing. Indexes in * it therefore have little to do with current varattno values. As above, * entries are unique unless this is for an unnamed JOIN RTE. (In such an * RTE, we never actually print this array, but we must compute it anyway * for possible use in computing column names of upper joins.) The * parallel array is_new_col marks which of these columns are new since * original parsing. Entries with is_new_col false must match the * non-NULL colnames entries one-for-one. */ int num_new_cols; /* length of new_colnames[] array */ char **new_colnames; /* array of C strings */ bool *is_new_col; /* array of bool flags */ /* This flag tells whether we should actually print a column alias list */ bool printaliases; /* This list has all names used as USING names in joins above this RTE */ List *parentUsing; /* names assigned to parent merged columns */ /* * If this struct is for a JOIN RTE, we fill these fields during the * set_using_names() pass to describe its relationship to its child RTEs. * * leftattnos and rightattnos are arrays with one entry per existing * output column of the join (hence, indexable by join varattno). For a * simple reference to a column of the left child, leftattnos[i] is the * child RTE's attno and rightattnos[i] is zero; and conversely for a * column of the right child. But for merged columns produced by JOIN * USING/NATURAL JOIN, both leftattnos[i] and rightattnos[i] are nonzero. * Also, if the column has been dropped, both are zero. * * If it's a JOIN USING, usingNames holds the alias names selected for the * merged columns (these might be different from the original USING list, * if we had to modify names to achieve uniqueness). */ int leftrti; /* rangetable index of left child */ int rightrti; /* rangetable index of right child */ int *leftattnos; /* left-child varattnos of join cols, or 0 */ int *rightattnos; /* right-child varattnos of join cols, or 0 */ List *usingNames; /* names assigned to merged columns */ } deparse_columns; /* This macro is analogous to rt_fetch(), but for deparse_columns structs */ #define deparse_columns_fetch(rangetable_index, dpns) \ ((deparse_columns *) list_nth((dpns)->rtable_columns, (rangetable_index)-1)) /* * Entry in set_rtable_names' hash table */ typedef struct { char name[NAMEDATALEN]; /* Hash key --- must be first */ int counter; /* Largest addition used so far for name */ } NameHashEntry; /* ---------- * Global data * ---------- */ static SPIPlanPtr plan_getrulebyoid = NULL; static const char *query_getrulebyoid = "SELECT * FROM pg_catalog.pg_rewrite WHERE oid = $1"; static SPIPlanPtr plan_getviewrule = NULL; static const char *query_getviewrule = "SELECT * FROM pg_catalog.pg_rewrite WHERE ev_class = $1 AND rulename = $2"; /* GUC parameters */ bool quote_all_identifiers = false; /* ---------- * Local functions * * Most of these functions used to use fixed-size buffers to build their * results. Now, they take an (already initialized) StringInfo object * as a parameter, and append their text output to its contents. * ---------- */ static char *deparse_expression_pretty(Node *expr, List *dpcontext, bool forceprefix, bool showimplicit, int prettyFlags, int startIndent); static char *pg_get_viewdef_worker(Oid viewoid, int prettyFlags, int wrapColumn); static char *pg_get_triggerdef_worker(Oid trigid, bool pretty); static void decompile_column_index_array(Datum column_index_array, Oid relId, StringInfo buf); static char *pg_get_ruledef_worker(Oid ruleoid, int prettyFlags); static char *pg_get_indexdef_worker(Oid indexrelid, int colno, const Oid *excludeOps, bool attrsOnly, bool showTblSpc, int prettyFlags); static char *pg_get_constraintdef_worker(Oid constraintId, bool fullCommand, int prettyFlags); static text *pg_get_expr_worker(text *expr, Oid relid, const char *relname, int prettyFlags); static int print_function_arguments(StringInfo buf, HeapTuple proctup, bool print_table_args, bool print_defaults); static void print_function_rettype(StringInfo buf, HeapTuple proctup); static void print_function_trftypes(StringInfo buf, HeapTuple proctup); static void set_rtable_names(deparse_namespace *dpns, List *parent_namespaces, Bitmapset *rels_used); static void set_deparse_for_query(deparse_namespace *dpns, Query *query, List *parent_namespaces); static void set_simple_column_names(deparse_namespace *dpns); static bool has_dangerous_join_using(deparse_namespace *dpns, Node *jtnode); static void set_using_names(deparse_namespace *dpns, Node *jtnode, List *parentUsing); static void set_relation_column_names(deparse_namespace *dpns, RangeTblEntry *rte, deparse_columns *colinfo); static void set_join_column_names(deparse_namespace *dpns, RangeTblEntry *rte, deparse_columns *colinfo); static bool colname_is_unique(char *colname, deparse_namespace *dpns, deparse_columns *colinfo); static char *make_colname_unique(char *colname, deparse_namespace *dpns, deparse_columns *colinfo); static void expand_colnames_array_to(deparse_columns *colinfo, int n); static void identify_join_columns(JoinExpr *j, RangeTblEntry *jrte, deparse_columns *colinfo); static void flatten_join_using_qual(Node *qual, List **leftvars, List **rightvars); static char *get_rtable_name(int rtindex, deparse_context *context); static void set_deparse_planstate(deparse_namespace *dpns, PlanState *ps); static void push_child_plan(deparse_namespace *dpns, PlanState *ps, deparse_namespace *save_dpns); static void pop_child_plan(deparse_namespace *dpns, deparse_namespace *save_dpns); static void push_ancestor_plan(deparse_namespace *dpns, ListCell *ancestor_cell, deparse_namespace *save_dpns); static void pop_ancestor_plan(deparse_namespace *dpns, deparse_namespace *save_dpns); static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc, int prettyFlags); static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc, int prettyFlags, int wrapColumn); static void get_query_def(Query *query, StringInfo buf, List *parentnamespace, TupleDesc resultDesc, int prettyFlags, int wrapColumn, int startIndent); static void get_values_def(List *values_lists, deparse_context *context); static void get_with_clause(Query *query, deparse_context *context); static void get_select_query_def(Query *query, deparse_context *context, TupleDesc resultDesc); static void get_insert_query_def(Query *query, deparse_context *context); static void get_update_query_def(Query *query, deparse_context *context); static void get_update_query_targetlist_def(Query *query, List *targetList, deparse_context *context, RangeTblEntry *rte); static void get_delete_query_def(Query *query, deparse_context *context); static void get_utility_query_def(Query *query, deparse_context *context); static void get_basic_select_query(Query *query, deparse_context *context, TupleDesc resultDesc); static void get_target_list(List *targetList, deparse_context *context, TupleDesc resultDesc); static void get_setop_query(Node *setOp, Query *query, deparse_context *context, TupleDesc resultDesc); static Node *get_rule_sortgroupclause(Index ref, List *tlist, bool force_colno, deparse_context *context); static void get_rule_groupingset(GroupingSet *gset, List *targetlist, bool omit_parens, deparse_context *context); static void get_rule_orderby(List *orderList, List *targetList, bool force_colno, deparse_context *context); static void get_rule_windowclause(Query *query, deparse_context *context); static void get_rule_windowspec(WindowClause *wc, List *targetList, deparse_context *context); static char *get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context); static Node *find_param_referent(Param *param, deparse_context *context, deparse_namespace **dpns_p, ListCell **ancestor_cell_p); static void get_parameter(Param *param, deparse_context *context); static const char *get_simple_binary_op_name(OpExpr *expr); static bool isSimpleNode(Node *node, Node *parentNode, int prettyFlags); static void appendContextKeyword(deparse_context *context, const char *str, int indentBefore, int indentAfter, int indentPlus); static void removeStringInfoSpaces(StringInfo str); static void get_rule_expr(Node *node, deparse_context *context, bool showimplicit); static void get_rule_expr_toplevel(Node *node, deparse_context *context, bool showimplicit); static void get_oper_expr(OpExpr *expr, deparse_context *context); static void get_func_expr(FuncExpr *expr, deparse_context *context, bool showimplicit); static void get_agg_expr(Aggref *aggref, deparse_context *context); static void get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context); static void get_coercion_expr(Node *arg, deparse_context *context, Oid resulttype, int32 resulttypmod, Node *parentNode); static void get_const_expr(Const *constval, deparse_context *context, int showtype); static void get_const_collation(Const *constval, deparse_context *context); static void simple_quote_literal(StringInfo buf, const char *val); static void get_sublink_expr(SubLink *sublink, deparse_context *context); static void get_from_clause(Query *query, const char *prefix, deparse_context *context); static void get_from_clause_item(Node *jtnode, Query *query, deparse_context *context); static void get_column_alias_list(deparse_columns *colinfo, deparse_context *context); static void get_from_clause_coldeflist(RangeTblFunction *rtfunc, deparse_columns *colinfo, deparse_context *context); static void get_tablesample_def(TableSampleClause *tablesample, deparse_context *context); static void get_opclass_name(Oid opclass, Oid actual_datatype, StringInfo buf); static Node *processIndirection(Node *node, deparse_context *context, bool printit); static void printSubscripts(ArrayRef *aref, deparse_context *context); static char *get_relation_name(Oid relid); static char *generate_relation_name(Oid relid, List *namespaces); static char *generate_qualified_relation_name(Oid relid); static char *generate_function_name(Oid funcid, int nargs, List *argnames, Oid *argtypes, bool has_variadic, bool *use_variadic_p, ParseExprKind special_exprkind); static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2); static text *string_to_text(char *str); static char *flatten_reloptions(Oid relid); #define only_marker(rte) ((rte)->inh ? "" : "ONLY ") /* ---------- * get_ruledef - Do it all and return a text * that could be used as a statement * to recreate the rule * ---------- */ Datum pg_get_ruledef(PG_FUNCTION_ARGS) { Oid ruleoid = PG_GETARG_OID(0); int prettyFlags; prettyFlags = PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, prettyFlags))); } Datum pg_get_ruledef_ext(PG_FUNCTION_ARGS) { Oid ruleoid = PG_GETARG_OID(0); bool pretty = PG_GETARG_BOOL(1); int prettyFlags; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, prettyFlags))); } static char * pg_get_ruledef_worker(Oid ruleoid, int prettyFlags) { Datum args[1]; char nulls[1]; int spirc; HeapTuple ruletup; TupleDesc rulettc; StringInfoData buf; /* * Do this first so that string is alloc'd in outer context not SPI's. */ initStringInfo(&buf); /* * Connect to SPI manager */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "SPI_connect failed"); /* * On the first call prepare the plan to lookup pg_rewrite. We read * pg_rewrite over the SPI manager instead of using the syscache to be * checked for read access on pg_rewrite. */ if (plan_getrulebyoid == NULL) { Oid argtypes[1]; SPIPlanPtr plan; argtypes[0] = OIDOID; plan = SPI_prepare(query_getrulebyoid, 1, argtypes); if (plan == NULL) elog(ERROR, "SPI_prepare failed for \"%s\"", query_getrulebyoid); SPI_keepplan(plan); plan_getrulebyoid = plan; } /* * Get the pg_rewrite tuple for this rule */ args[0] = ObjectIdGetDatum(ruleoid); nulls[0] = ' '; spirc = SPI_execute_plan(plan_getrulebyoid, args, nulls, true, 0); if (spirc != SPI_OK_SELECT) elog(ERROR, "failed to get pg_rewrite tuple for rule %u", ruleoid); if (SPI_processed != 1) appendStringInfoChar(&buf, '-'); else { /* * Get the rule's definition and put it into executor's memory */ ruletup = SPI_tuptable->vals[0]; rulettc = SPI_tuptable->tupdesc; make_ruledef(&buf, ruletup, rulettc, prettyFlags); } /* * Disconnect from SPI manager */ if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "SPI_finish failed"); return buf.data; } /* ---------- * get_viewdef - Mainly the same thing, but we * only return the SELECT part of a view * ---------- */ Datum pg_get_viewdef(PG_FUNCTION_ARGS) { /* By OID */ Oid viewoid = PG_GETARG_OID(0); int prettyFlags; prettyFlags = PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT))); } Datum pg_get_viewdef_ext(PG_FUNCTION_ARGS) { /* By OID */ Oid viewoid = PG_GETARG_OID(0); bool pretty = PG_GETARG_BOOL(1); int prettyFlags; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT))); } Datum pg_get_viewdef_wrap(PG_FUNCTION_ARGS) { /* By OID */ Oid viewoid = PG_GETARG_OID(0); int wrap = PG_GETARG_INT32(1); int prettyFlags; /* calling this implies we want pretty printing */ prettyFlags = PRETTYFLAG_PAREN | PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, wrap))); } Datum pg_get_viewdef_name(PG_FUNCTION_ARGS) { /* By qualified name */ text *viewname = PG_GETARG_TEXT_P(0); int prettyFlags; RangeVar *viewrel; Oid viewoid; prettyFlags = PRETTYFLAG_INDENT; /* Look up view name. Can't lock it - we might not have privileges. */ viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname)); viewoid = RangeVarGetRelid(viewrel, NoLock, false); PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT))); } Datum pg_get_viewdef_name_ext(PG_FUNCTION_ARGS) { /* By qualified name */ text *viewname = PG_GETARG_TEXT_P(0); bool pretty = PG_GETARG_BOOL(1); int prettyFlags; RangeVar *viewrel; Oid viewoid; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; /* Look up view name. Can't lock it - we might not have privileges. */ viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname)); viewoid = RangeVarGetRelid(viewrel, NoLock, false); PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags, WRAP_COLUMN_DEFAULT))); } /* * Common code for by-OID and by-name variants of pg_get_viewdef */ static char * pg_get_viewdef_worker(Oid viewoid, int prettyFlags, int wrapColumn) { Datum args[2]; char nulls[2]; int spirc; HeapTuple ruletup; TupleDesc rulettc; StringInfoData buf; /* * Do this first so that string is alloc'd in outer context not SPI's. */ initStringInfo(&buf); /* * Connect to SPI manager */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "SPI_connect failed"); /* * On the first call prepare the plan to lookup pg_rewrite. We read * pg_rewrite over the SPI manager instead of using the syscache to be * checked for read access on pg_rewrite. */ if (plan_getviewrule == NULL) { Oid argtypes[2]; SPIPlanPtr plan; argtypes[0] = OIDOID; argtypes[1] = NAMEOID; plan = SPI_prepare(query_getviewrule, 2, argtypes); if (plan == NULL) elog(ERROR, "SPI_prepare failed for \"%s\"", query_getviewrule); SPI_keepplan(plan); plan_getviewrule = plan; } /* * Get the pg_rewrite tuple for the view's SELECT rule */ args[0] = ObjectIdGetDatum(viewoid); args[1] = DirectFunctionCall1(namein, CStringGetDatum(ViewSelectRuleName)); nulls[0] = ' '; nulls[1] = ' '; spirc = SPI_execute_plan(plan_getviewrule, args, nulls, true, 0); if (spirc != SPI_OK_SELECT) elog(ERROR, "failed to get pg_rewrite tuple for view %u", viewoid); if (SPI_processed != 1) appendStringInfoString(&buf, "Not a view"); else { /* * Get the rule's definition and put it into executor's memory */ ruletup = SPI_tuptable->vals[0]; rulettc = SPI_tuptable->tupdesc; make_viewdef(&buf, ruletup, rulettc, prettyFlags, wrapColumn); } /* * Disconnect from SPI manager */ if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "SPI_finish failed"); return buf.data; } /* ---------- * get_triggerdef - Get the definition of a trigger * ---------- */ Datum pg_get_triggerdef(PG_FUNCTION_ARGS) { Oid trigid = PG_GETARG_OID(0); PG_RETURN_TEXT_P(string_to_text(pg_get_triggerdef_worker(trigid, false))); } Datum pg_get_triggerdef_ext(PG_FUNCTION_ARGS) { Oid trigid = PG_GETARG_OID(0); bool pretty = PG_GETARG_BOOL(1); PG_RETURN_TEXT_P(string_to_text(pg_get_triggerdef_worker(trigid, pretty))); } static char * pg_get_triggerdef_worker(Oid trigid, bool pretty) { HeapTuple ht_trig; Form_pg_trigger trigrec; StringInfoData buf; Relation tgrel; ScanKeyData skey[1]; SysScanDesc tgscan; int findx = 0; char *tgname; Oid argtypes[1]; /* dummy */ Datum value; bool isnull; /* * Fetch the pg_trigger tuple by the Oid of the trigger */ tgrel = heap_open(TriggerRelationId, AccessShareLock); ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(trigid)); tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, NULL, 1, skey); ht_trig = systable_getnext(tgscan); if (!HeapTupleIsValid(ht_trig)) elog(ERROR, "could not find tuple for trigger %u", trigid); trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig); /* * Start the trigger definition. Note that the trigger's name should never * be schema-qualified, but the trigger rel's name may be. */ initStringInfo(&buf); tgname = NameStr(trigrec->tgname); appendStringInfo(&buf, "CREATE %sTRIGGER %s ", OidIsValid(trigrec->tgconstraint) ? "CONSTRAINT " : "", quote_identifier(tgname)); if (TRIGGER_FOR_BEFORE(trigrec->tgtype)) appendStringInfoString(&buf, "BEFORE"); else if (TRIGGER_FOR_AFTER(trigrec->tgtype)) appendStringInfoString(&buf, "AFTER"); else if (TRIGGER_FOR_INSTEAD(trigrec->tgtype)) appendStringInfoString(&buf, "INSTEAD OF"); else elog(ERROR, "unexpected tgtype value: %d", trigrec->tgtype); if (TRIGGER_FOR_INSERT(trigrec->tgtype)) { appendStringInfoString(&buf, " INSERT"); findx++; } if (TRIGGER_FOR_DELETE(trigrec->tgtype)) { if (findx > 0) appendStringInfoString(&buf, " OR DELETE"); else appendStringInfoString(&buf, " DELETE"); findx++; } if (TRIGGER_FOR_UPDATE(trigrec->tgtype)) { if (findx > 0) appendStringInfoString(&buf, " OR UPDATE"); else appendStringInfoString(&buf, " UPDATE"); findx++; /* tgattr is first var-width field, so OK to access directly */ if (trigrec->tgattr.dim1 > 0) { int i; appendStringInfoString(&buf, " OF "); for (i = 0; i < trigrec->tgattr.dim1; i++) { char *attname; if (i > 0) appendStringInfoString(&buf, ", "); attname = get_relid_attribute_name(trigrec->tgrelid, trigrec->tgattr.values[i]); appendStringInfoString(&buf, quote_identifier(attname)); } } } if (TRIGGER_FOR_TRUNCATE(trigrec->tgtype)) { if (findx > 0) appendStringInfoString(&buf, " OR TRUNCATE"); else appendStringInfoString(&buf, " TRUNCATE"); findx++; } appendStringInfo(&buf, " ON %s ", generate_relation_name(trigrec->tgrelid, NIL)); if (OidIsValid(trigrec->tgconstraint)) { if (OidIsValid(trigrec->tgconstrrelid)) appendStringInfo(&buf, "FROM %s ", generate_relation_name(trigrec->tgconstrrelid, NIL)); if (!trigrec->tgdeferrable) appendStringInfoString(&buf, "NOT "); appendStringInfoString(&buf, "DEFERRABLE INITIALLY "); if (trigrec->tginitdeferred) appendStringInfoString(&buf, "DEFERRED "); else appendStringInfoString(&buf, "IMMEDIATE "); } if (TRIGGER_FOR_ROW(trigrec->tgtype)) appendStringInfoString(&buf, "FOR EACH ROW "); else appendStringInfoString(&buf, "FOR EACH STATEMENT "); /* If the trigger has a WHEN qualification, add that */ value = fastgetattr(ht_trig, Anum_pg_trigger_tgqual, tgrel->rd_att, &isnull); if (!isnull) { Node *qual; char relkind; deparse_context context; deparse_namespace dpns; RangeTblEntry *oldrte; RangeTblEntry *newrte; appendStringInfoString(&buf, "WHEN ("); qual = stringToNode(TextDatumGetCString(value)); relkind = get_rel_relkind(trigrec->tgrelid); /* Build minimal OLD and NEW RTEs for the rel */ oldrte = makeNode(RangeTblEntry); oldrte->rtekind = RTE_RELATION; oldrte->relid = trigrec->tgrelid; oldrte->relkind = relkind; oldrte->alias = makeAlias("old", NIL); oldrte->eref = oldrte->alias; oldrte->lateral = false; oldrte->inh = false; oldrte->inFromCl = true; newrte = makeNode(RangeTblEntry); newrte->rtekind = RTE_RELATION; newrte->relid = trigrec->tgrelid; newrte->relkind = relkind; newrte->alias = makeAlias("new", NIL); newrte->eref = newrte->alias; newrte->lateral = false; newrte->inh = false; newrte->inFromCl = true; /* Build two-element rtable */ memset(&dpns, 0, sizeof(dpns)); dpns.rtable = list_make2(oldrte, newrte); dpns.ctes = NIL; set_rtable_names(&dpns, NIL, NULL); set_simple_column_names(&dpns); /* Set up context with one-deep namespace stack */ context.buf = &buf; context.namespaces = list_make1(&dpns); context.windowClause = NIL; context.windowTList = NIL; context.varprefix = true; context.prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; context.wrapColumn = WRAP_COLUMN_DEFAULT; context.indentLevel = PRETTYINDENT_STD; context.special_exprkind = EXPR_KIND_NONE; get_rule_expr(qual, &context, false); appendStringInfoString(&buf, ") "); } appendStringInfo(&buf, "EXECUTE PROCEDURE %s(", generate_function_name(trigrec->tgfoid, 0, NIL, argtypes, false, NULL, EXPR_KIND_NONE)); if (trigrec->tgnargs > 0) { char *p; int i; value = fastgetattr(ht_trig, Anum_pg_trigger_tgargs, tgrel->rd_att, &isnull); if (isnull) elog(ERROR, "tgargs is null for trigger %u", trigid); p = (char *) VARDATA(DatumGetByteaP(value)); for (i = 0; i < trigrec->tgnargs; i++) { if (i > 0) appendStringInfoString(&buf, ", "); simple_quote_literal(&buf, p); /* advance p to next string embedded in tgargs */ while (*p) p++; p++; } } /* We deliberately do not put semi-colon at end */ appendStringInfoChar(&buf, ')'); /* Clean up */ systable_endscan(tgscan); heap_close(tgrel, AccessShareLock); return buf.data; } /* ---------- * get_indexdef - Get the definition of an index * * In the extended version, there is a colno argument as well as pretty bool. * if colno == 0, we want a complete index definition. * if colno > 0, we only want the Nth index key's variable or expression. * * Note that the SQL-function versions of this omit any info about the * index tablespace; this is intentional because pg_dump wants it that way. * However pg_get_indexdef_string() includes index tablespace if not default. * ---------- */ Datum pg_get_indexdef(PG_FUNCTION_ARGS) { Oid indexrelid = PG_GETARG_OID(0); int prettyFlags; prettyFlags = PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0, NULL, false, false, prettyFlags))); } Datum pg_get_indexdef_ext(PG_FUNCTION_ARGS) { Oid indexrelid = PG_GETARG_OID(0); int32 colno = PG_GETARG_INT32(1); bool pretty = PG_GETARG_BOOL(2); int prettyFlags; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno, NULL, colno != 0, false, prettyFlags))); } /* Internal version that returns a palloc'd C string; no pretty-printing */ char * pg_get_indexdef_string(Oid indexrelid) { return pg_get_indexdef_worker(indexrelid, 0, NULL, false, true, 0); } /* Internal version that just reports the column definitions */ char * pg_get_indexdef_columns(Oid indexrelid, bool pretty) { int prettyFlags; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; return pg_get_indexdef_worker(indexrelid, 0, NULL, true, false, prettyFlags); } /* * Internal workhorse to decompile an index definition. * * This is now used for exclusion constraints as well: if excludeOps is not * NULL then it points to an array of exclusion operator OIDs. */ static char * pg_get_indexdef_worker(Oid indexrelid, int colno, const Oid *excludeOps, bool attrsOnly, bool showTblSpc, int prettyFlags) { /* might want a separate isConstraint parameter later */ bool isConstraint = (excludeOps != NULL); HeapTuple ht_idx; HeapTuple ht_idxrel; HeapTuple ht_am; Form_pg_index idxrec; Form_pg_class idxrelrec; Form_pg_am amrec; List *indexprs; ListCell *indexpr_item; List *context; Oid indrelid; int keyno; Datum indcollDatum; Datum indclassDatum; Datum indoptionDatum; bool isnull; oidvector *indcollation; oidvector *indclass; int2vector *indoption; StringInfoData buf; char *str; char *sep; /* * Fetch the pg_index tuple by the Oid of the index */ ht_idx = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexrelid)); if (!HeapTupleIsValid(ht_idx)) elog(ERROR, "cache lookup failed for index %u", indexrelid); idxrec = (Form_pg_index) GETSTRUCT(ht_idx); indrelid = idxrec->indrelid; Assert(indexrelid == idxrec->indexrelid); /* Must get indcollation, indclass, and indoption the hard way */ indcollDatum = SysCacheGetAttr(INDEXRELID, ht_idx, Anum_pg_index_indcollation, &isnull); Assert(!isnull); indcollation = (oidvector *) DatumGetPointer(indcollDatum); indclassDatum = SysCacheGetAttr(INDEXRELID, ht_idx, Anum_pg_index_indclass, &isnull); Assert(!isnull); indclass = (oidvector *) DatumGetPointer(indclassDatum); indoptionDatum = SysCacheGetAttr(INDEXRELID, ht_idx, Anum_pg_index_indoption, &isnull); Assert(!isnull); indoption = (int2vector *) DatumGetPointer(indoptionDatum); /* * Fetch the pg_class tuple of the index relation */ ht_idxrel = SearchSysCache1(RELOID, ObjectIdGetDatum(indexrelid)); if (!HeapTupleIsValid(ht_idxrel)) elog(ERROR, "cache lookup failed for relation %u", indexrelid); idxrelrec = (Form_pg_class) GETSTRUCT(ht_idxrel); /* * Fetch the pg_am tuple of the index' access method */ ht_am = SearchSysCache1(AMOID, ObjectIdGetDatum(idxrelrec->relam)); if (!HeapTupleIsValid(ht_am)) elog(ERROR, "cache lookup failed for access method %u", idxrelrec->relam); amrec = (Form_pg_am) GETSTRUCT(ht_am); /* * Get the index expressions, if any. (NOTE: we do not use the relcache * versions of the expressions and predicate, because we want to display * non-const-folded expressions.) */ if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs)) { Datum exprsDatum; bool isnull; char *exprsString; exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx, Anum_pg_index_indexprs, &isnull); Assert(!isnull); exprsString = TextDatumGetCString(exprsDatum); indexprs = (List *) stringToNode(exprsString); pfree(exprsString); } else indexprs = NIL; indexpr_item = list_head(indexprs); context = deparse_context_for(get_relation_name(indrelid), indrelid); /* * Start the index definition. Note that the index's name should never be * schema-qualified, but the indexed rel's name may be. */ initStringInfo(&buf); if (!attrsOnly) { if (!isConstraint) appendStringInfo(&buf, "CREATE %sINDEX %s ON %s USING %s (", idxrec->indisunique ? "UNIQUE " : "", quote_identifier(NameStr(idxrelrec->relname)), generate_relation_name(indrelid, NIL), quote_identifier(NameStr(amrec->amname))); else /* currently, must be EXCLUDE constraint */ appendStringInfo(&buf, "EXCLUDE USING %s (", quote_identifier(NameStr(amrec->amname))); } /* * Report the indexed attributes */ sep = ""; for (keyno = 0; keyno < idxrec->indnatts; keyno++) { AttrNumber attnum = idxrec->indkey.values[keyno]; int16 opt = indoption->values[keyno]; Oid keycoltype; Oid keycolcollation; if (!colno) appendStringInfoString(&buf, sep); sep = ", "; if (attnum != 0) { /* Simple index column */ char *attname; int32 keycoltypmod; attname = get_relid_attribute_name(indrelid, attnum); if (!colno || colno == keyno + 1) appendStringInfoString(&buf, quote_identifier(attname)); get_atttypetypmodcoll(indrelid, attnum, &keycoltype, &keycoltypmod, &keycolcollation); } else { /* expressional index */ Node *indexkey; if (indexpr_item == NULL) elog(ERROR, "too few entries in indexprs list"); indexkey = (Node *) lfirst(indexpr_item); indexpr_item = lnext(indexpr_item); /* Deparse */ str = deparse_expression_pretty(indexkey, context, false, false, prettyFlags, 0); if (!colno || colno == keyno + 1) { /* Need parens if it's not a bare function call */ if (indexkey && IsA(indexkey, FuncExpr) && ((FuncExpr *) indexkey)->funcformat == COERCE_EXPLICIT_CALL) appendStringInfoString(&buf, str); else appendStringInfo(&buf, "(%s)", str); } keycoltype = exprType(indexkey); keycolcollation = exprCollation(indexkey); } if (!attrsOnly && (!colno || colno == keyno + 1)) { Oid indcoll; /* Add collation, if not default for column */ indcoll = indcollation->values[keyno]; if (OidIsValid(indcoll) && indcoll != keycolcollation) appendStringInfo(&buf, " COLLATE %s", generate_collation_name((indcoll))); /* Add the operator class name, if not default */ get_opclass_name(indclass->values[keyno], keycoltype, &buf); /* Add options if relevant */ if (amrec->amcanorder) { /* if it supports sort ordering, report DESC and NULLS opts */ if (opt & INDOPTION_DESC) { appendStringInfoString(&buf, " DESC"); /* NULLS FIRST is the default in this case */ if (!(opt & INDOPTION_NULLS_FIRST)) appendStringInfoString(&buf, " NULLS LAST"); } else { if (opt & INDOPTION_NULLS_FIRST) appendStringInfoString(&buf, " NULLS FIRST"); } } /* Add the exclusion operator if relevant */ if (excludeOps != NULL) appendStringInfo(&buf, " WITH %s", generate_operator_name(excludeOps[keyno], keycoltype, keycoltype)); } } if (!attrsOnly) { appendStringInfoChar(&buf, ')'); /* * If it has options, append "WITH (options)" */ str = flatten_reloptions(indexrelid); if (str) { appendStringInfo(&buf, " WITH (%s)", str); pfree(str); } /* * If it's in a nondefault tablespace, say so, but only if requested */ if (showTblSpc) { Oid tblspc; tblspc = get_rel_tablespace(indexrelid); if (OidIsValid(tblspc)) { if (isConstraint) appendStringInfoString(&buf, " USING INDEX"); appendStringInfo(&buf, " TABLESPACE %s", quote_identifier(get_tablespace_name(tblspc))); } } /* * If it's a partial index, decompile and append the predicate */ if (!heap_attisnull(ht_idx, Anum_pg_index_indpred)) { Node *node; Datum predDatum; bool isnull; char *predString; /* Convert text string to node tree */ predDatum = SysCacheGetAttr(INDEXRELID, ht_idx, Anum_pg_index_indpred, &isnull); Assert(!isnull); predString = TextDatumGetCString(predDatum); node = (Node *) stringToNode(predString); pfree(predString); /* Deparse */ str = deparse_expression_pretty(node, context, false, false, prettyFlags, 0); if (isConstraint) appendStringInfo(&buf, " WHERE (%s)", str); else appendStringInfo(&buf, " WHERE %s", str); } } /* Clean up */ ReleaseSysCache(ht_idx); ReleaseSysCache(ht_idxrel); ReleaseSysCache(ht_am); return buf.data; } /* * pg_get_constraintdef * * Returns the definition for the constraint, ie, everything that needs to * appear after "ALTER TABLE ... ADD CONSTRAINT ". */ Datum pg_get_constraintdef(PG_FUNCTION_ARGS) { Oid constraintId = PG_GETARG_OID(0); int prettyFlags; prettyFlags = PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId, false, prettyFlags))); } Datum pg_get_constraintdef_ext(PG_FUNCTION_ARGS) { Oid constraintId = PG_GETARG_OID(0); bool pretty = PG_GETARG_BOOL(1); int prettyFlags; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId, false, prettyFlags))); } /* * Internal version that returns a full ALTER TABLE ... ADD CONSTRAINT command */ char * pg_get_constraintdef_command(Oid constraintId) { return pg_get_constraintdef_worker(constraintId, true, 0); } /* * As of 9.4, we now use an MVCC snapshot for this. */ static char * pg_get_constraintdef_worker(Oid constraintId, bool fullCommand, int prettyFlags) { HeapTuple tup; Form_pg_constraint conForm; StringInfoData buf; SysScanDesc scandesc; ScanKeyData scankey[1]; Snapshot snapshot = RegisterSnapshot(GetTransactionSnapshot()); Relation relation = heap_open(ConstraintRelationId, AccessShareLock); ScanKeyInit(&scankey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(constraintId)); scandesc = systable_beginscan(relation, ConstraintOidIndexId, true, snapshot, 1, scankey); /* * We later use the tuple with SysCacheGetAttr() as if we had obtained it * via SearchSysCache, which works fine. */ tup = systable_getnext(scandesc); UnregisterSnapshot(snapshot); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for constraint %u", constraintId); conForm = (Form_pg_constraint) GETSTRUCT(tup); initStringInfo(&buf); if (fullCommand) { /* * Currently, callers want ALTER TABLE (without ONLY) for CHECK * constraints, and other types of constraints don't inherit anyway so * it doesn't matter whether we say ONLY or not. Someday we might * need to let callers specify whether to put ONLY in the command. */ appendStringInfo(&buf, "ALTER TABLE %s ADD CONSTRAINT %s ", generate_qualified_relation_name(conForm->conrelid), quote_identifier(NameStr(conForm->conname))); } switch (conForm->contype) { case CONSTRAINT_FOREIGN: { Datum val; bool isnull; const char *string; /* Start off the constraint definition */ appendStringInfoString(&buf, "FOREIGN KEY ("); /* Fetch and build referencing-column list */ val = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_conkey, &isnull); if (isnull) elog(ERROR, "null conkey for constraint %u", constraintId); decompile_column_index_array(val, conForm->conrelid, &buf); /* add foreign relation name */ appendStringInfo(&buf, ") REFERENCES %s(", generate_relation_name(conForm->confrelid, NIL)); /* Fetch and build referenced-column list */ val = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_confkey, &isnull); if (isnull) elog(ERROR, "null confkey for constraint %u", constraintId); decompile_column_index_array(val, conForm->confrelid, &buf); appendStringInfoChar(&buf, ')'); /* Add match type */ switch (conForm->confmatchtype) { case FKCONSTR_MATCH_FULL: string = " MATCH FULL"; break; case FKCONSTR_MATCH_PARTIAL: string = " MATCH PARTIAL"; break; case FKCONSTR_MATCH_SIMPLE: string = ""; break; default: elog(ERROR, "unrecognized confmatchtype: %d", conForm->confmatchtype); string = ""; /* keep compiler quiet */ break; } appendStringInfoString(&buf, string); /* Add ON UPDATE and ON DELETE clauses, if needed */ switch (conForm->confupdtype) { case FKCONSTR_ACTION_NOACTION: string = NULL; /* suppress default */ break; case FKCONSTR_ACTION_RESTRICT: string = "RESTRICT"; break; case FKCONSTR_ACTION_CASCADE: string = "CASCADE"; break; case FKCONSTR_ACTION_SETNULL: string = "SET NULL"; break; case FKCONSTR_ACTION_SETDEFAULT: string = "SET DEFAULT"; break; default: elog(ERROR, "unrecognized confupdtype: %d", conForm->confupdtype); string = NULL; /* keep compiler quiet */ break; } if (string) appendStringInfo(&buf, " ON UPDATE %s", string); switch (conForm->confdeltype) { case FKCONSTR_ACTION_NOACTION: string = NULL; /* suppress default */ break; case FKCONSTR_ACTION_RESTRICT: string = "RESTRICT"; break; case FKCONSTR_ACTION_CASCADE: string = "CASCADE"; break; case FKCONSTR_ACTION_SETNULL: string = "SET NULL"; break; case FKCONSTR_ACTION_SETDEFAULT: string = "SET DEFAULT"; break; default: elog(ERROR, "unrecognized confdeltype: %d", conForm->confdeltype); string = NULL; /* keep compiler quiet */ break; } if (string) appendStringInfo(&buf, " ON DELETE %s", string); break; } case CONSTRAINT_PRIMARY: case CONSTRAINT_UNIQUE: { Datum val; bool isnull; Oid indexId; /* Start off the constraint definition */ if (conForm->contype == CONSTRAINT_PRIMARY) appendStringInfoString(&buf, "PRIMARY KEY ("); else appendStringInfoString(&buf, "UNIQUE ("); /* Fetch and build target column list */ val = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_conkey, &isnull); if (isnull) elog(ERROR, "null conkey for constraint %u", constraintId); decompile_column_index_array(val, conForm->conrelid, &buf); appendStringInfoChar(&buf, ')'); indexId = get_constraint_index(constraintId); /* XXX why do we only print these bits if fullCommand? */ if (fullCommand && OidIsValid(indexId)) { char *options = flatten_reloptions(indexId); Oid tblspc; if (options) { appendStringInfo(&buf, " WITH (%s)", options); pfree(options); } tblspc = get_rel_tablespace(indexId); if (OidIsValid(tblspc)) appendStringInfo(&buf, " USING INDEX TABLESPACE %s", quote_identifier(get_tablespace_name(tblspc))); } break; } case CONSTRAINT_CHECK: { Datum val; bool isnull; char *conbin; char *consrc; Node *expr; List *context; /* Fetch constraint expression in parsetree form */ val = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_conbin, &isnull); if (isnull) elog(ERROR, "null conbin for constraint %u", constraintId); conbin = TextDatumGetCString(val); expr = stringToNode(conbin); /* Set up deparsing context for Var nodes in constraint */ if (conForm->conrelid != InvalidOid) { /* relation constraint */ context = deparse_context_for(get_relation_name(conForm->conrelid), conForm->conrelid); } else { /* domain constraint --- can't have Vars */ context = NIL; } consrc = deparse_expression_pretty(expr, context, false, false, prettyFlags, 0); /* * Now emit the constraint definition, adding NO INHERIT if * necessary. * * There are cases where the constraint expression will be * fully parenthesized and we don't need the outer parens ... * but there are other cases where we do need 'em. Be * conservative for now. * * Note that simply checking for leading '(' and trailing ')' * would NOT be good enough, consider "(x > 0) AND (y > 0)". */ appendStringInfo(&buf, "CHECK (%s)%s", consrc, conForm->connoinherit ? " NO INHERIT" : ""); break; } case CONSTRAINT_TRIGGER: /* * There isn't an ALTER TABLE syntax for creating a user-defined * constraint trigger, but it seems better to print something than * throw an error; if we throw error then this function couldn't * safely be applied to all rows of pg_constraint. */ appendStringInfoString(&buf, "TRIGGER"); break; case CONSTRAINT_EXCLUSION: { Oid indexOid = conForm->conindid; Datum val; bool isnull; Datum *elems; int nElems; int i; Oid *operators; /* Extract operator OIDs from the pg_constraint tuple */ val = SysCacheGetAttr(CONSTROID, tup, Anum_pg_constraint_conexclop, &isnull); if (isnull) elog(ERROR, "null conexclop for constraint %u", constraintId); deconstruct_array(DatumGetArrayTypeP(val), OIDOID, sizeof(Oid), true, 'i', &elems, NULL, &nElems); operators = (Oid *) palloc(nElems * sizeof(Oid)); for (i = 0; i < nElems; i++) operators[i] = DatumGetObjectId(elems[i]); /* pg_get_indexdef_worker does the rest */ /* suppress tablespace because pg_dump wants it that way */ appendStringInfoString(&buf, pg_get_indexdef_worker(indexOid, 0, operators, false, false, prettyFlags)); break; } default: elog(ERROR, "invalid constraint type \"%c\"", conForm->contype); break; } if (conForm->condeferrable) appendStringInfoString(&buf, " DEFERRABLE"); if (conForm->condeferred) appendStringInfoString(&buf, " INITIALLY DEFERRED"); if (!conForm->convalidated) appendStringInfoString(&buf, " NOT VALID"); /* Cleanup */ systable_endscan(scandesc); heap_close(relation, AccessShareLock); return buf.data; } /* * Convert an int16[] Datum into a comma-separated list of column names * for the indicated relation; append the list to buf. */ static void decompile_column_index_array(Datum column_index_array, Oid relId, StringInfo buf) { Datum *keys; int nKeys; int j; /* Extract data from array of int16 */ deconstruct_array(DatumGetArrayTypeP(column_index_array), INT2OID, 2, true, 's', &keys, NULL, &nKeys); for (j = 0; j < nKeys; j++) { char *colName; colName = get_relid_attribute_name(relId, DatumGetInt16(keys[j])); if (j == 0) appendStringInfoString(buf, quote_identifier(colName)); else appendStringInfo(buf, ", %s", quote_identifier(colName)); } } /* ---------- * get_expr - Decompile an expression tree * * Input: an expression tree in nodeToString form, and a relation OID * * Output: reverse-listed expression * * Currently, the expression can only refer to a single relation, namely * the one specified by the second parameter. This is sufficient for * partial indexes, column default expressions, etc. We also support * Var-free expressions, for which the OID can be InvalidOid. * ---------- */ Datum pg_get_expr(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_P(0); Oid relid = PG_GETARG_OID(1); int prettyFlags; char *relname; prettyFlags = PRETTYFLAG_INDENT; if (OidIsValid(relid)) { /* Get the name for the relation */ relname = get_rel_name(relid); /* * If the OID isn't actually valid, don't throw an error, just return * NULL. This is a bit questionable, but it's what we've done * historically, and it can help avoid unwanted failures when * examining catalog entries for just-deleted relations. */ if (relname == NULL) PG_RETURN_NULL(); } else relname = NULL; PG_RETURN_TEXT_P(pg_get_expr_worker(expr, relid, relname, prettyFlags)); } Datum pg_get_expr_ext(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_P(0); Oid relid = PG_GETARG_OID(1); bool pretty = PG_GETARG_BOOL(2); int prettyFlags; char *relname; prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : PRETTYFLAG_INDENT; if (OidIsValid(relid)) { /* Get the name for the relation */ relname = get_rel_name(relid); /* See notes above */ if (relname == NULL) PG_RETURN_NULL(); } else relname = NULL; PG_RETURN_TEXT_P(pg_get_expr_worker(expr, relid, relname, prettyFlags)); } static text * pg_get_expr_worker(text *expr, Oid relid, const char *relname, int prettyFlags) { Node *node; List *context; char *exprstr; char *str; /* Convert input TEXT object to C string */ exprstr = text_to_cstring(expr); /* Convert expression to node tree */ node = (Node *) stringToNode(exprstr); pfree(exprstr); /* Prepare deparse context if needed */ if (OidIsValid(relid)) context = deparse_context_for(relname, relid); else context = NIL; /* Deparse */ str = deparse_expression_pretty(node, context, false, false, prettyFlags, 0); return string_to_text(str); } /* ---------- * get_userbyid - Get a user name by roleid and * fallback to 'unknown (OID=n)' * ---------- */ Datum pg_get_userbyid(PG_FUNCTION_ARGS) { Oid roleid = PG_GETARG_OID(0); Name result; HeapTuple roletup; Form_pg_authid role_rec; /* * Allocate space for the result */ result = (Name) palloc(NAMEDATALEN); memset(NameStr(*result), 0, NAMEDATALEN); /* * Get the pg_authid entry and print the result */ roletup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid)); if (HeapTupleIsValid(roletup)) { role_rec = (Form_pg_authid) GETSTRUCT(roletup); StrNCpy(NameStr(*result), NameStr(role_rec->rolname), NAMEDATALEN); ReleaseSysCache(roletup); } else sprintf(NameStr(*result), "unknown (OID=%u)", roleid); PG_RETURN_NAME(result); } /* * pg_get_serial_sequence * Get the name of the sequence used by a serial column, * formatted suitably for passing to setval, nextval or currval. * First parameter is not treated as double-quoted, second parameter * is --- see documentation for reason. */ Datum pg_get_serial_sequence(PG_FUNCTION_ARGS) { text *tablename = PG_GETARG_TEXT_P(0); text *columnname = PG_GETARG_TEXT_PP(1); RangeVar *tablerv; Oid tableOid; char *column; AttrNumber attnum; Oid sequenceId = InvalidOid; Relation depRel; ScanKeyData key[3]; SysScanDesc scan; HeapTuple tup; /* Look up table name. Can't lock it - we might not have privileges. */ tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename)); tableOid = RangeVarGetRelid(tablerv, NoLock, false); /* Get the number of the column */ column = text_to_cstring(columnname); attnum = get_attnum(tableOid, column); if (attnum == InvalidAttrNumber) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", column, tablerv->relname))); /* Search the dependency table for the dependent sequence */ depRel = heap_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableOid)); ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(attnum)); scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup); /* * We assume any auto dependency of a sequence on a column must be * what we are looking for. (We need the relkind test because indexes * can also have auto dependencies on columns.) */ if (deprec->classid == RelationRelationId && deprec->objsubid == 0 && deprec->deptype == DEPENDENCY_AUTO && get_rel_relkind(deprec->objid) == RELKIND_SEQUENCE) { sequenceId = deprec->objid; break; } } systable_endscan(scan); heap_close(depRel, AccessShareLock); if (OidIsValid(sequenceId)) { char *result; result = generate_qualified_relation_name(sequenceId); PG_RETURN_TEXT_P(string_to_text(result)); } PG_RETURN_NULL(); } /* * pg_get_functiondef * Returns the complete "CREATE OR REPLACE FUNCTION ..." statement for * the specified function. * * Note: if you change the output format of this function, be careful not * to break psql's rules (in \ef and \sf) for identifying the start of the * function body. To wit: the function body starts on a line that begins * with "AS ", and no preceding line will look like that. */ Datum pg_get_functiondef(PG_FUNCTION_ARGS) { Oid funcid = PG_GETARG_OID(0); StringInfoData buf; StringInfoData dq; HeapTuple proctup; Form_pg_proc proc; Datum tmp; bool isnull; const char *prosrc; const char *name; const char *nsp; float4 procost; int oldlen; initStringInfo(&buf); /* Look up the function */ proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); proc = (Form_pg_proc) GETSTRUCT(proctup); name = NameStr(proc->proname); if (proc->proisagg) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is an aggregate function", name))); /* * We always qualify the function name, to ensure the right function gets * replaced. */ nsp = get_namespace_name(proc->pronamespace); appendStringInfo(&buf, "CREATE OR REPLACE FUNCTION %s(", quote_qualified_identifier(nsp, name)); (void) print_function_arguments(&buf, proctup, false, true); appendStringInfoString(&buf, ")\n RETURNS "); print_function_rettype(&buf, proctup); print_function_trftypes(&buf, proctup); appendStringInfo(&buf, "\n LANGUAGE %s\n", quote_identifier(get_language_name(proc->prolang, false))); /* Emit some miscellaneous options on one line */ oldlen = buf.len; if (proc->proiswindow) appendStringInfoString(&buf, " WINDOW"); switch (proc->provolatile) { case PROVOLATILE_IMMUTABLE: appendStringInfoString(&buf, " IMMUTABLE"); break; case PROVOLATILE_STABLE: appendStringInfoString(&buf, " STABLE"); break; case PROVOLATILE_VOLATILE: break; } if (proc->proisstrict) appendStringInfoString(&buf, " STRICT"); if (proc->prosecdef) appendStringInfoString(&buf, " SECURITY DEFINER"); if (proc->proleakproof) appendStringInfoString(&buf, " LEAKPROOF"); /* This code for the default cost and rows should match functioncmds.c */ if (proc->prolang == INTERNALlanguageId || proc->prolang == ClanguageId) procost = 1; else procost = 100; if (proc->procost != procost) appendStringInfo(&buf, " COST %g", proc->procost); if (proc->prorows > 0 && proc->prorows != 1000) appendStringInfo(&buf, " ROWS %g", proc->prorows); if (oldlen != buf.len) appendStringInfoChar(&buf, '\n'); /* Emit any proconfig options, one per line */ tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proconfig, &isnull); if (!isnull) { ArrayType *a = DatumGetArrayTypeP(tmp); int i; Assert(ARR_ELEMTYPE(a) == TEXTOID); Assert(ARR_NDIM(a) == 1); Assert(ARR_LBOUND(a)[0] == 1); for (i = 1; i <= ARR_DIMS(a)[0]; i++) { Datum d; d = array_ref(a, 1, &i, -1 /* varlenarray */ , -1 /* TEXT's typlen */ , false /* TEXT's typbyval */ , 'i' /* TEXT's typalign */ , &isnull); if (!isnull) { char *configitem = TextDatumGetCString(d); char *pos; pos = strchr(configitem, '='); if (pos == NULL) continue; *pos++ = '\0'; appendStringInfo(&buf, " SET %s TO ", quote_identifier(configitem)); /* * Some GUC variable names are 'LIST' type and hence must not * be quoted. */ if (pg_strcasecmp(configitem, "DateStyle") == 0 || pg_strcasecmp(configitem, "search_path") == 0) appendStringInfoString(&buf, pos); else simple_quote_literal(&buf, pos); appendStringInfoChar(&buf, '\n'); } } } /* And finally the function definition ... */ appendStringInfoString(&buf, "AS "); tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_probin, &isnull); if (!isnull) { simple_quote_literal(&buf, TextDatumGetCString(tmp)); appendStringInfoString(&buf, ", "); /* assume prosrc isn't null */ } tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_prosrc, &isnull); if (isnull) elog(ERROR, "null prosrc"); prosrc = TextDatumGetCString(tmp); /* * We always use dollar quoting. Figure out a suitable delimiter. * * Since the user is likely to be editing the function body string, we * shouldn't use a short delimiter that he might easily create a conflict * with. Hence prefer "$function$", but extend if needed. */ initStringInfo(&dq); appendStringInfoString(&dq, "$function"); while (strstr(prosrc, dq.data) != NULL) appendStringInfoChar(&dq, 'x'); appendStringInfoChar(&dq, '$'); appendStringInfoString(&buf, dq.data); appendStringInfoString(&buf, prosrc); appendStringInfoString(&buf, dq.data); appendStringInfoChar(&buf, '\n'); ReleaseSysCache(proctup); PG_RETURN_TEXT_P(string_to_text(buf.data)); } /* * pg_get_function_arguments * Get a nicely-formatted list of arguments for a function. * This is everything that would go between the parentheses in * CREATE FUNCTION. */ Datum pg_get_function_arguments(PG_FUNCTION_ARGS) { Oid funcid = PG_GETARG_OID(0); StringInfoData buf; HeapTuple proctup; initStringInfo(&buf); proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); (void) print_function_arguments(&buf, proctup, false, true); ReleaseSysCache(proctup); PG_RETURN_TEXT_P(string_to_text(buf.data)); } /* * pg_get_function_identity_arguments * Get a formatted list of arguments for a function. * This is everything that would go between the parentheses in * ALTER FUNCTION, etc. In particular, don't print defaults. */ Datum pg_get_function_identity_arguments(PG_FUNCTION_ARGS) { Oid funcid = PG_GETARG_OID(0); StringInfoData buf; HeapTuple proctup; initStringInfo(&buf); proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); (void) print_function_arguments(&buf, proctup, false, false); ReleaseSysCache(proctup); PG_RETURN_TEXT_P(string_to_text(buf.data)); } /* * pg_get_function_result * Get a nicely-formatted version of the result type of a function. * This is what would appear after RETURNS in CREATE FUNCTION. */ Datum pg_get_function_result(PG_FUNCTION_ARGS) { Oid funcid = PG_GETARG_OID(0); StringInfoData buf; HeapTuple proctup; initStringInfo(&buf); proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); print_function_rettype(&buf, proctup); ReleaseSysCache(proctup); PG_RETURN_TEXT_P(string_to_text(buf.data)); } /* * Guts of pg_get_function_result: append the function's return type * to the specified buffer. */ static void print_function_rettype(StringInfo buf, HeapTuple proctup) { Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(proctup); int ntabargs = 0; StringInfoData rbuf; initStringInfo(&rbuf); if (proc->proretset) { /* It might be a table function; try to print the arguments */ appendStringInfoString(&rbuf, "TABLE("); ntabargs = print_function_arguments(&rbuf, proctup, true, false); if (ntabargs > 0) appendStringInfoChar(&rbuf, ')'); else resetStringInfo(&rbuf); } if (ntabargs == 0) { /* Not a table function, so do the normal thing */ if (proc->proretset) appendStringInfoString(&rbuf, "SETOF "); appendStringInfoString(&rbuf, format_type_be(proc->prorettype)); } appendStringInfoString(buf, rbuf.data); } /* * Common code for pg_get_function_arguments and pg_get_function_result: * append the desired subset of arguments to buf. We print only TABLE * arguments when print_table_args is true, and all the others when it's false. * We print argument defaults only if print_defaults is true. * Function return value is the number of arguments printed. */ static int print_function_arguments(StringInfo buf, HeapTuple proctup, bool print_table_args, bool print_defaults) { Form_pg_proc proc = (Form_pg_proc) GETSTRUCT(proctup); int numargs; Oid *argtypes; char **argnames; char *argmodes; int insertorderbyat = -1; int argsprinted; int inputargno; int nlackdefaults; ListCell *nextargdefault = NULL; int i; numargs = get_func_arg_info(proctup, &argtypes, &argnames, &argmodes); nlackdefaults = numargs; if (print_defaults && proc->pronargdefaults > 0) { Datum proargdefaults; bool isnull; proargdefaults = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proargdefaults, &isnull); if (!isnull) { char *str; List *argdefaults; str = TextDatumGetCString(proargdefaults); argdefaults = (List *) stringToNode(str); Assert(IsA(argdefaults, List)); pfree(str); nextargdefault = list_head(argdefaults); /* nlackdefaults counts only *input* arguments lacking defaults */ nlackdefaults = proc->pronargs - list_length(argdefaults); } } /* Check for special treatment of ordered-set aggregates */ if (proc->proisagg) { HeapTuple aggtup; Form_pg_aggregate agg; aggtup = SearchSysCache1(AGGFNOID, ObjectIdGetDatum(HeapTupleGetOid(proctup))); if (!HeapTupleIsValid(aggtup)) elog(ERROR, "cache lookup failed for aggregate %u", HeapTupleGetOid(proctup)); agg = (Form_pg_aggregate) GETSTRUCT(aggtup); if (AGGKIND_IS_ORDERED_SET(agg->aggkind)) insertorderbyat = agg->aggnumdirectargs; ReleaseSysCache(aggtup); } argsprinted = 0; inputargno = 0; for (i = 0; i < numargs; i++) { Oid argtype = argtypes[i]; char *argname = argnames ? argnames[i] : NULL; char argmode = argmodes ? argmodes[i] : PROARGMODE_IN; const char *modename; bool isinput; switch (argmode) { case PROARGMODE_IN: modename = ""; isinput = true; break; case PROARGMODE_INOUT: modename = "INOUT "; isinput = true; break; case PROARGMODE_OUT: modename = "OUT "; isinput = false; break; case PROARGMODE_VARIADIC: modename = "VARIADIC "; isinput = true; break; case PROARGMODE_TABLE: modename = ""; isinput = false; break; default: elog(ERROR, "invalid parameter mode '%c'", argmode); modename = NULL; /* keep compiler quiet */ isinput = false; break; } if (isinput) inputargno++; /* this is a 1-based counter */ if (print_table_args != (argmode == PROARGMODE_TABLE)) continue; if (argsprinted == insertorderbyat) { if (argsprinted) appendStringInfoChar(buf, ' '); appendStringInfoString(buf, "ORDER BY "); } else if (argsprinted) appendStringInfoString(buf, ", "); appendStringInfoString(buf, modename); if (argname && argname[0]) appendStringInfo(buf, "%s ", quote_identifier(argname)); appendStringInfoString(buf, format_type_be(argtype)); if (print_defaults && isinput && inputargno > nlackdefaults) { Node *expr; Assert(nextargdefault != NULL); expr = (Node *) lfirst(nextargdefault); nextargdefault = lnext(nextargdefault); appendStringInfo(buf, " DEFAULT %s", deparse_expression(expr, NIL, false, false)); } argsprinted++; /* nasty hack: print the last arg twice for variadic ordered-set agg */ if (argsprinted == insertorderbyat && i == numargs - 1) { i--; /* aggs shouldn't have defaults anyway, but just to be sure ... */ print_defaults = false; } } return argsprinted; } static bool is_input_argument(int nth, const char *argmodes) { return (!argmodes || argmodes[nth] == PROARGMODE_IN || argmodes[nth] == PROARGMODE_INOUT || argmodes[nth] == PROARGMODE_VARIADIC); } /* * Append used transformated types to specified buffer */ static void print_function_trftypes(StringInfo buf, HeapTuple proctup) { Oid *trftypes; int ntypes; ntypes = get_func_trftypes(proctup, &trftypes); if (ntypes > 0) { int i; appendStringInfoString(buf, "\n TRANSFORM "); for (i = 0; i < ntypes; i++) { if (i != 0) appendStringInfoString(buf, ", "); appendStringInfo(buf, "FOR TYPE %s", format_type_be(trftypes[i])); } } } /* * Get textual representation of a function argument's default value. The * second argument of this function is the argument number among all arguments * (i.e. proallargtypes, *not* proargtypes), starting with 1, because that's * how information_schema.sql uses it. */ Datum pg_get_function_arg_default(PG_FUNCTION_ARGS) { Oid funcid = PG_GETARG_OID(0); int32 nth_arg = PG_GETARG_INT32(1); HeapTuple proctup; Form_pg_proc proc; int numargs; Oid *argtypes; char **argnames; char *argmodes; int i; List *argdefaults; Node *node; char *str; int nth_inputarg; Datum proargdefaults; bool isnull; int nth_default; proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); numargs = get_func_arg_info(proctup, &argtypes, &argnames, &argmodes); if (nth_arg < 1 || nth_arg > numargs || !is_input_argument(nth_arg - 1, argmodes)) { ReleaseSysCache(proctup); PG_RETURN_NULL(); } nth_inputarg = 0; for (i = 0; i < nth_arg; i++) if (is_input_argument(i, argmodes)) nth_inputarg++; proargdefaults = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proargdefaults, &isnull); if (isnull) { ReleaseSysCache(proctup); PG_RETURN_NULL(); } str = TextDatumGetCString(proargdefaults); argdefaults = (List *) stringToNode(str); Assert(IsA(argdefaults, List)); pfree(str); proc = (Form_pg_proc) GETSTRUCT(proctup); /* * Calculate index into proargdefaults: proargdefaults corresponds to the * last N input arguments, where N = pronargdefaults. */ nth_default = nth_inputarg - 1 - (proc->pronargs - proc->pronargdefaults); if (nth_default < 0 || nth_default >= list_length(argdefaults)) { ReleaseSysCache(proctup); PG_RETURN_NULL(); } node = list_nth(argdefaults, nth_default); str = deparse_expression(node, NIL, false, false); ReleaseSysCache(proctup); PG_RETURN_TEXT_P(string_to_text(str)); } /* * deparse_expression - General utility for deparsing expressions * * calls deparse_expression_pretty with all prettyPrinting disabled */ char * deparse_expression(Node *expr, List *dpcontext, bool forceprefix, bool showimplicit) { return deparse_expression_pretty(expr, dpcontext, forceprefix, showimplicit, 0, 0); } /* ---------- * deparse_expression_pretty - General utility for deparsing expressions * * expr is the node tree to be deparsed. It must be a transformed expression * tree (ie, not the raw output of gram.y). * * dpcontext is a list of deparse_namespace nodes representing the context * for interpreting Vars in the node tree. It can be NIL if no Vars are * expected. * * forceprefix is TRUE to force all Vars to be prefixed with their table names. * * showimplicit is TRUE to force all implicit casts to be shown explicitly. * * Tries to pretty up the output according to prettyFlags and startIndent. * * The result is a palloc'd string. * ---------- */ static char * deparse_expression_pretty(Node *expr, List *dpcontext, bool forceprefix, bool showimplicit, int prettyFlags, int startIndent) { StringInfoData buf; deparse_context context; initStringInfo(&buf); context.buf = &buf; context.namespaces = dpcontext; context.windowClause = NIL; context.windowTList = NIL; context.varprefix = forceprefix; context.prettyFlags = prettyFlags; context.wrapColumn = WRAP_COLUMN_DEFAULT; context.indentLevel = startIndent; context.special_exprkind = EXPR_KIND_NONE; get_rule_expr(expr, &context, showimplicit); return buf.data; } /* ---------- * deparse_context_for - Build deparse context for a single relation * * Given the reference name (alias) and OID of a relation, build deparsing * context for an expression referencing only that relation (as varno 1, * varlevelsup 0). This is sufficient for many uses of deparse_expression. * ---------- */ List * deparse_context_for(const char *aliasname, Oid relid) { deparse_namespace *dpns; RangeTblEntry *rte; dpns = (deparse_namespace *) palloc0(sizeof(deparse_namespace)); /* Build a minimal RTE for the rel */ rte = makeNode(RangeTblEntry); rte->rtekind = RTE_RELATION; rte->relid = relid; rte->relkind = RELKIND_RELATION; /* no need for exactness here */ rte->alias = makeAlias(aliasname, NIL); rte->eref = rte->alias; rte->lateral = false; rte->inh = false; rte->inFromCl = true; /* Build one-element rtable */ dpns->rtable = list_make1(rte); dpns->ctes = NIL; set_rtable_names(dpns, NIL, NULL); set_simple_column_names(dpns); /* Return a one-deep namespace stack */ return list_make1(dpns); } /* * deparse_context_for_plan_rtable - Build deparse context for a plan's rtable * * When deparsing an expression in a Plan tree, we use the plan's rangetable * to resolve names of simple Vars. The initialization of column names for * this is rather expensive if the rangetable is large, and it'll be the same * for every expression in the Plan tree; so we do it just once and re-use * the result of this function for each expression. (Note that the result * is not usable until set_deparse_context_planstate() is applied to it.) * * In addition to the plan's rangetable list, pass the per-RTE alias names * assigned by a previous call to select_rtable_names_for_explain. */ List * deparse_context_for_plan_rtable(List *rtable, List *rtable_names) { deparse_namespace *dpns; dpns = (deparse_namespace *) palloc0(sizeof(deparse_namespace)); /* Initialize fields that stay the same across the whole plan tree */ dpns->rtable = rtable; dpns->rtable_names = rtable_names; dpns->ctes = NIL; /* * Set up column name aliases. We will get rather bogus results for join * RTEs, but that doesn't matter because plan trees don't contain any join * alias Vars. */ set_simple_column_names(dpns); /* Return a one-deep namespace stack */ return list_make1(dpns); } /* * set_deparse_context_planstate - Specify Plan node containing expression * * When deparsing an expression in a Plan tree, we might have to resolve * OUTER_VAR, INNER_VAR, or INDEX_VAR references. To do this, the caller must * provide the parent PlanState node. Then OUTER_VAR and INNER_VAR references * can be resolved by drilling down into the left and right child plans. * Similarly, INDEX_VAR references can be resolved by reference to the * indextlist given in a parent IndexOnlyScan node, or to the scan tlist in * ForeignScan and CustomScan nodes. (Note that we don't currently support * deparsing of indexquals in regular IndexScan or BitmapIndexScan nodes; * for those, we can only deparse the indexqualorig fields, which won't * contain INDEX_VAR Vars.) * * Note: planstate really ought to be declared as "PlanState *", but we use * "Node *" to avoid having to include execnodes.h in ruleutils.h. * * The ancestors list is a list of the PlanState's parent PlanStates, the * most-closely-nested first. This is needed to resolve PARAM_EXEC Params. * Note we assume that all the PlanStates share the same rtable. * * Once this function has been called, deparse_expression() can be called on * subsidiary expression(s) of the specified PlanState node. To deparse * expressions of a different Plan node in the same Plan tree, re-call this * function to identify the new parent Plan node. * * The result is the same List passed in; this is a notational convenience. */ List * set_deparse_context_planstate(List *dpcontext, Node *planstate, List *ancestors) { deparse_namespace *dpns; /* Should always have one-entry namespace list for Plan deparsing */ Assert(list_length(dpcontext) == 1); dpns = (deparse_namespace *) linitial(dpcontext); /* Set our attention on the specific plan node passed in */ set_deparse_planstate(dpns, (PlanState *) planstate); dpns->ancestors = ancestors; return dpcontext; } /* * select_rtable_names_for_explain - Select RTE aliases for EXPLAIN * * Determine the relation aliases we'll use during an EXPLAIN operation. * This is just a frontend to set_rtable_names. We have to expose the aliases * to EXPLAIN because EXPLAIN needs to know the right alias names to print. */ List * select_rtable_names_for_explain(List *rtable, Bitmapset *rels_used) { deparse_namespace dpns; memset(&dpns, 0, sizeof(dpns)); dpns.rtable = rtable; dpns.ctes = NIL; set_rtable_names(&dpns, NIL, rels_used); /* We needn't bother computing column aliases yet */ return dpns.rtable_names; } /* * set_rtable_names: select RTE aliases to be used in printing a query * * We fill in dpns->rtable_names with a list of names that is one-for-one with * the already-filled dpns->rtable list. Each RTE name is unique among those * in the new namespace plus any ancestor namespaces listed in * parent_namespaces. * * If rels_used isn't NULL, only RTE indexes listed in it are given aliases. * * Note that this function is only concerned with relation names, not column * names. */ static void set_rtable_names(deparse_namespace *dpns, List *parent_namespaces, Bitmapset *rels_used) { HASHCTL hash_ctl; HTAB *names_hash; NameHashEntry *hentry; bool found; int rtindex; ListCell *lc; dpns->rtable_names = NIL; /* nothing more to do if empty rtable */ if (dpns->rtable == NIL) return; /* * We use a hash table to hold known names, so that this process is O(N) * not O(N^2) for N names. */ MemSet(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = NAMEDATALEN; hash_ctl.entrysize = sizeof(NameHashEntry); hash_ctl.hcxt = CurrentMemoryContext; names_hash = hash_create("set_rtable_names names", list_length(dpns->rtable), &hash_ctl, HASH_ELEM | HASH_CONTEXT); /* Preload the hash table with names appearing in parent_namespaces */ foreach(lc, parent_namespaces) { deparse_namespace *olddpns = (deparse_namespace *) lfirst(lc); ListCell *lc2; foreach(lc2, olddpns->rtable_names) { char *oldname = (char *) lfirst(lc2); if (oldname == NULL) continue; hentry = (NameHashEntry *) hash_search(names_hash, oldname, HASH_ENTER, &found); /* we do not complain about duplicate names in parent namespaces */ hentry->counter = 0; } } /* Now we can scan the rtable */ rtindex = 1; foreach(lc, dpns->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); char *refname; /* Just in case this takes an unreasonable amount of time ... */ CHECK_FOR_INTERRUPTS(); if (rels_used && !bms_is_member(rtindex, rels_used)) { /* Ignore unreferenced RTE */ refname = NULL; } else if (rte->alias) { /* If RTE has a user-defined alias, prefer that */ refname = rte->alias->aliasname; } else if (rte->rtekind == RTE_RELATION) { /* Use the current actual name of the relation */ refname = get_rel_name(rte->relid); } else if (rte->rtekind == RTE_JOIN) { /* Unnamed join has no refname */ refname = NULL; } else { /* Otherwise use whatever the parser assigned */ refname = rte->eref->aliasname; } /* * If the selected name isn't unique, append digits to make it so, and * make a new hash entry for it once we've got a unique name. For a * very long input name, we might have to truncate to stay within * NAMEDATALEN. */ if (refname) { hentry = (NameHashEntry *) hash_search(names_hash, refname, HASH_ENTER, &found); if (found) { /* Name already in use, must choose a new one */ int refnamelen = strlen(refname); char *modname = (char *) palloc(refnamelen + 16); NameHashEntry *hentry2; do { hentry->counter++; for (;;) { /* * We avoid using %.*s here because it can misbehave * if the data is not valid in what libc thinks is the * prevailing encoding. */ memcpy(modname, refname, refnamelen); sprintf(modname + refnamelen, "_%d", hentry->counter); if (strlen(modname) < NAMEDATALEN) break; /* drop chars from refname to keep all the digits */ refnamelen = pg_mbcliplen(refname, refnamelen, refnamelen - 1); } hentry2 = (NameHashEntry *) hash_search(names_hash, modname, HASH_ENTER, &found); } while (found); hentry2->counter = 0; /* init new hash entry */ refname = modname; } else { /* Name not previously used, need only initialize hentry */ hentry->counter = 0; } } dpns->rtable_names = lappend(dpns->rtable_names, refname); rtindex++; } hash_destroy(names_hash); } /* * set_deparse_for_query: set up deparse_namespace for deparsing a Query tree * * For convenience, this is defined to initialize the deparse_namespace struct * from scratch. */ static void set_deparse_for_query(deparse_namespace *dpns, Query *query, List *parent_namespaces) { ListCell *lc; ListCell *lc2; /* Initialize *dpns and fill rtable/ctes links */ memset(dpns, 0, sizeof(deparse_namespace)); dpns->rtable = query->rtable; dpns->ctes = query->cteList; /* Assign a unique relation alias to each RTE */ set_rtable_names(dpns, parent_namespaces, NULL); /* Initialize dpns->rtable_columns to contain zeroed structs */ dpns->rtable_columns = NIL; while (list_length(dpns->rtable_columns) < list_length(dpns->rtable)) dpns->rtable_columns = lappend(dpns->rtable_columns, palloc0(sizeof(deparse_columns))); /* If it's a utility query, it won't have a jointree */ if (query->jointree) { /* Detect whether global uniqueness of USING names is needed */ dpns->unique_using = has_dangerous_join_using(dpns, (Node *) query->jointree); /* * Select names for columns merged by USING, via a recursive pass over * the query jointree. */ set_using_names(dpns, (Node *) query->jointree, NIL); } /* * Now assign remaining column aliases for each RTE. We do this in a * linear scan of the rtable, so as to process RTEs whether or not they * are in the jointree (we mustn't miss NEW.*, INSERT target relations, * etc). JOIN RTEs must be processed after their children, but this is * okay because they appear later in the rtable list than their children * (cf Asserts in identify_join_columns()). */ forboth(lc, dpns->rtable, lc2, dpns->rtable_columns) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); deparse_columns *colinfo = (deparse_columns *) lfirst(lc2); if (rte->rtekind == RTE_JOIN) set_join_column_names(dpns, rte, colinfo); else set_relation_column_names(dpns, rte, colinfo); } } /* * set_simple_column_names: fill in column aliases for non-query situations * * This handles EXPLAIN and cases where we only have relation RTEs. Without * a join tree, we can't do anything smart about join RTEs, but we don't * need to (note that EXPLAIN should never see join alias Vars anyway). * If we do hit a join RTE we'll just process it like a non-table base RTE. */ static void set_simple_column_names(deparse_namespace *dpns) { ListCell *lc; ListCell *lc2; /* Initialize dpns->rtable_columns to contain zeroed structs */ dpns->rtable_columns = NIL; while (list_length(dpns->rtable_columns) < list_length(dpns->rtable)) dpns->rtable_columns = lappend(dpns->rtable_columns, palloc0(sizeof(deparse_columns))); /* Assign unique column aliases within each RTE */ forboth(lc, dpns->rtable, lc2, dpns->rtable_columns) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); deparse_columns *colinfo = (deparse_columns *) lfirst(lc2); set_relation_column_names(dpns, rte, colinfo); } } /* * has_dangerous_join_using: search jointree for unnamed JOIN USING * * Merged columns of a JOIN USING may act differently from either of the input * columns, either because they are merged with COALESCE (in a FULL JOIN) or * because an implicit coercion of the underlying input column is required. * In such a case the column must be referenced as a column of the JOIN not as * a column of either input. And this is problematic if the join is unnamed * (alias-less): we cannot qualify the column's name with an RTE name, since * there is none. (Forcibly assigning an alias to the join is not a solution, * since that will prevent legal references to tables below the join.) * To ensure that every column in the query is unambiguously referenceable, * we must assign such merged columns names that are globally unique across * the whole query, aliasing other columns out of the way as necessary. * * Because the ensuing re-aliasing is fairly damaging to the readability of * the query, we don't do this unless we have to. So, we must pre-scan * the join tree to see if we have to, before starting set_using_names(). */ static bool has_dangerous_join_using(deparse_namespace *dpns, Node *jtnode) { if (IsA(jtnode, RangeTblRef)) { /* nothing to do here */ } else if (IsA(jtnode, FromExpr)) { FromExpr *f = (FromExpr *) jtnode; ListCell *lc; foreach(lc, f->fromlist) { if (has_dangerous_join_using(dpns, (Node *) lfirst(lc))) return true; } } else if (IsA(jtnode, JoinExpr)) { JoinExpr *j = (JoinExpr *) jtnode; /* Is it an unnamed JOIN with USING? */ if (j->alias == NULL && j->usingClause) { /* * Yes, so check each join alias var to see if any of them are not * simple references to underlying columns. If so, we have a * dangerous situation and must pick unique aliases. */ RangeTblEntry *jrte = rt_fetch(j->rtindex, dpns->rtable); ListCell *lc; foreach(lc, jrte->joinaliasvars) { Var *aliasvar = (Var *) lfirst(lc); if (aliasvar != NULL && !IsA(aliasvar, Var)) return true; } } /* Nope, but inspect children */ if (has_dangerous_join_using(dpns, j->larg)) return true; if (has_dangerous_join_using(dpns, j->rarg)) return true; } else elog(ERROR, "unrecognized node type: %d", (int) nodeTag(jtnode)); return false; } /* * set_using_names: select column aliases to be used for merged USING columns * * We do this during a recursive descent of the query jointree. * dpns->unique_using must already be set to determine the global strategy. * * Column alias info is saved in the dpns->rtable_columns list, which is * assumed to be filled with pre-zeroed deparse_columns structs. * * parentUsing is a list of all USING aliases assigned in parent joins of * the current jointree node. (The passed-in list must not be modified.) */ static void set_using_names(deparse_namespace *dpns, Node *jtnode, List *parentUsing) { if (IsA(jtnode, RangeTblRef)) { /* nothing to do now */ } else if (IsA(jtnode, FromExpr)) { FromExpr *f = (FromExpr *) jtnode; ListCell *lc; foreach(lc, f->fromlist) set_using_names(dpns, (Node *) lfirst(lc), parentUsing); } else if (IsA(jtnode, JoinExpr)) { JoinExpr *j = (JoinExpr *) jtnode; RangeTblEntry *rte = rt_fetch(j->rtindex, dpns->rtable); deparse_columns *colinfo = deparse_columns_fetch(j->rtindex, dpns); int *leftattnos; int *rightattnos; deparse_columns *leftcolinfo; deparse_columns *rightcolinfo; int i; ListCell *lc; /* Get info about the shape of the join */ identify_join_columns(j, rte, colinfo); leftattnos = colinfo->leftattnos; rightattnos = colinfo->rightattnos; /* Look up the not-yet-filled-in child deparse_columns structs */ leftcolinfo = deparse_columns_fetch(colinfo->leftrti, dpns); rightcolinfo = deparse_columns_fetch(colinfo->rightrti, dpns); /* * If this join is unnamed, then we cannot substitute new aliases at * this level, so any name requirements pushed down to here must be * pushed down again to the children. */ if (rte->alias == NULL) { for (i = 0; i < colinfo->num_cols; i++) { char *colname = colinfo->colnames[i]; if (colname == NULL) continue; /* Push down to left column, unless it's a system column */ if (leftattnos[i] > 0) { expand_colnames_array_to(leftcolinfo, leftattnos[i]); leftcolinfo->colnames[leftattnos[i] - 1] = colname; } /* Same on the righthand side */ if (rightattnos[i] > 0) { expand_colnames_array_to(rightcolinfo, rightattnos[i]); rightcolinfo->colnames[rightattnos[i] - 1] = colname; } } } /* * If there's a USING clause, select the USING column names and push * those names down to the children. We have two strategies: * * If dpns->unique_using is TRUE, we force all USING names to be * unique across the whole query level. In principle we'd only need * the names of dangerous USING columns to be globally unique, but to * safely assign all USING names in a single pass, we have to enforce * the same uniqueness rule for all of them. However, if a USING * column's name has been pushed down from the parent, we should use * it as-is rather than making a uniqueness adjustment. This is * necessary when we're at an unnamed join, and it creates no risk of * ambiguity. Also, if there's a user-written output alias for a * merged column, we prefer to use that rather than the input name; * this simplifies the logic and seems likely to lead to less aliasing * overall. * * If dpns->unique_using is FALSE, we only need USING names to be * unique within their own join RTE. We still need to honor * pushed-down names, though. * * Though significantly different in results, these two strategies are * implemented by the same code, with only the difference of whether * to put assigned names into dpns->using_names. */ if (j->usingClause) { /* Copy the input parentUsing list so we don't modify it */ parentUsing = list_copy(parentUsing); /* USING names must correspond to the first join output columns */ expand_colnames_array_to(colinfo, list_length(j->usingClause)); i = 0; foreach(lc, j->usingClause) { char *colname = strVal(lfirst(lc)); /* Assert it's a merged column */ Assert(leftattnos[i] != 0 && rightattnos[i] != 0); /* Adopt passed-down name if any, else select unique name */ if (colinfo->colnames[i] != NULL) colname = colinfo->colnames[i]; else { /* Prefer user-written output alias if any */ if (rte->alias && i < list_length(rte->alias->colnames)) colname = strVal(list_nth(rte->alias->colnames, i)); /* Make it appropriately unique */ colname = make_colname_unique(colname, dpns, colinfo); if (dpns->unique_using) dpns->using_names = lappend(dpns->using_names, colname); /* Save it as output column name, too */ colinfo->colnames[i] = colname; } /* Remember selected names for use later */ colinfo->usingNames = lappend(colinfo->usingNames, colname); parentUsing = lappend(parentUsing, colname); /* Push down to left column, unless it's a system column */ if (leftattnos[i] > 0) { expand_colnames_array_to(leftcolinfo, leftattnos[i]); leftcolinfo->colnames[leftattnos[i] - 1] = colname; } /* Same on the righthand side */ if (rightattnos[i] > 0) { expand_colnames_array_to(rightcolinfo, rightattnos[i]); rightcolinfo->colnames[rightattnos[i] - 1] = colname; } i++; } } /* Mark child deparse_columns structs with correct parentUsing info */ leftcolinfo->parentUsing = parentUsing; rightcolinfo->parentUsing = parentUsing; /* Now recursively assign USING column names in children */ set_using_names(dpns, j->larg, parentUsing); set_using_names(dpns, j->rarg, parentUsing); } else elog(ERROR, "unrecognized node type: %d", (int) nodeTag(jtnode)); } /* * set_relation_column_names: select column aliases for a non-join RTE * * Column alias info is saved in *colinfo, which is assumed to be pre-zeroed. * If any colnames entries are already filled in, those override local * choices. */ static void set_relation_column_names(deparse_namespace *dpns, RangeTblEntry *rte, deparse_columns *colinfo) { int ncolumns; char **real_colnames; bool changed_any; int noldcolumns; int i; int j; /* * Extract the RTE's "real" column names. This is comparable to * get_rte_attribute_name, except that it's important to disregard dropped * columns. We put NULL into the array for a dropped column. */ if (rte->rtekind == RTE_RELATION) { /* Relation --- look to the system catalogs for up-to-date info */ Relation rel; TupleDesc tupdesc; rel = relation_open(rte->relid, AccessShareLock); tupdesc = RelationGetDescr(rel); ncolumns = tupdesc->natts; real_colnames = (char **) palloc(ncolumns * sizeof(char *)); for (i = 0; i < ncolumns; i++) { if (tupdesc->attrs[i]->attisdropped) real_colnames[i] = NULL; else real_colnames[i] = pstrdup(NameStr(tupdesc->attrs[i]->attname)); } relation_close(rel, AccessShareLock); } else { /* Otherwise use the column names from eref */ ListCell *lc; ncolumns = list_length(rte->eref->colnames); real_colnames = (char **) palloc(ncolumns * sizeof(char *)); i = 0; foreach(lc, rte->eref->colnames) { /* * If the column name shown in eref is an empty string, then it's * a column that was dropped at the time of parsing the query, so * treat it as dropped. */ char *cname = strVal(lfirst(lc)); if (cname[0] == '\0') cname = NULL; real_colnames[i] = cname; i++; } } /* * Ensure colinfo->colnames has a slot for each column. (It could be long * enough already, if we pushed down a name for the last column.) Note: * it's possible that there are now more columns than there were when the * query was parsed, ie colnames could be longer than rte->eref->colnames. * We must assign unique aliases to the new columns too, else there could * be unresolved conflicts when the view/rule is reloaded. */ expand_colnames_array_to(colinfo, ncolumns); Assert(colinfo->num_cols == ncolumns); /* * Make sufficiently large new_colnames and is_new_col arrays, too. * * Note: because we leave colinfo->num_new_cols zero until after the loop, * colname_is_unique will not consult that array, which is fine because it * would only be duplicate effort. */ colinfo->new_colnames = (char **) palloc(ncolumns * sizeof(char *)); colinfo->is_new_col = (bool *) palloc(ncolumns * sizeof(bool)); /* * Scan the columns, select a unique alias for each one, and store it in * colinfo->colnames and colinfo->new_colnames. The former array has NULL * entries for dropped columns, the latter omits them. Also mark * new_colnames entries as to whether they are new since parse time; this * is the case for entries beyond the length of rte->eref->colnames. */ noldcolumns = list_length(rte->eref->colnames); changed_any = false; j = 0; for (i = 0; i < ncolumns; i++) { char *real_colname = real_colnames[i]; char *colname = colinfo->colnames[i]; /* Skip dropped columns */ if (real_colname == NULL) { Assert(colname == NULL); /* colnames[i] is already NULL */ continue; } /* If alias already assigned, that's what to use */ if (colname == NULL) { /* If user wrote an alias, prefer that over real column name */ if (rte->alias && i < list_length(rte->alias->colnames)) colname = strVal(list_nth(rte->alias->colnames, i)); else colname = real_colname; /* Unique-ify and insert into colinfo */ colname = make_colname_unique(colname, dpns, colinfo); colinfo->colnames[i] = colname; } /* Put names of non-dropped columns in new_colnames[] too */ colinfo->new_colnames[j] = colname; /* And mark them as new or not */ colinfo->is_new_col[j] = (i >= noldcolumns); j++; /* Remember if any assigned aliases differ from "real" name */ if (!changed_any && strcmp(colname, real_colname) != 0) changed_any = true; } /* * Set correct length for new_colnames[] array. (Note: if columns have * been added, colinfo->num_cols includes them, which is not really quite * right but is harmless, since any new columns must be at the end where * they won't affect varattnos of pre-existing columns.) */ colinfo->num_new_cols = j; /* * For a relation RTE, we need only print the alias column names if any * are different from the underlying "real" names. For a function RTE, * always emit a complete column alias list; this is to protect against * possible instability of the default column names (eg, from altering * parameter names). For other RTE types, print if we changed anything OR * if there were user-written column aliases (since the latter would be * part of the underlying "reality"). */ if (rte->rtekind == RTE_RELATION) colinfo->printaliases = changed_any; else if (rte->rtekind == RTE_FUNCTION) colinfo->printaliases = true; else if (rte->alias && rte->alias->colnames != NIL) colinfo->printaliases = true; else colinfo->printaliases = changed_any; } /* * set_join_column_names: select column aliases for a join RTE * * Column alias info is saved in *colinfo, which is assumed to be pre-zeroed. * If any colnames entries are already filled in, those override local * choices. Also, names for USING columns were already chosen by * set_using_names(). We further expect that column alias selection has been * completed for both input RTEs. */ static void set_join_column_names(deparse_namespace *dpns, RangeTblEntry *rte, deparse_columns *colinfo) { deparse_columns *leftcolinfo; deparse_columns *rightcolinfo; bool changed_any; int noldcolumns; int nnewcolumns; Bitmapset *leftmerged = NULL; Bitmapset *rightmerged = NULL; int i; int j; int ic; int jc; /* Look up the previously-filled-in child deparse_columns structs */ leftcolinfo = deparse_columns_fetch(colinfo->leftrti, dpns); rightcolinfo = deparse_columns_fetch(colinfo->rightrti, dpns); /* * Ensure colinfo->colnames has a slot for each column. (It could be long * enough already, if we pushed down a name for the last column.) Note: * it's possible that one or both inputs now have more columns than there * were when the query was parsed, but we'll deal with that below. We * only need entries in colnames for pre-existing columns. */ noldcolumns = list_length(rte->eref->colnames); expand_colnames_array_to(colinfo, noldcolumns); Assert(colinfo->num_cols == noldcolumns); /* * Scan the join output columns, select an alias for each one, and store * it in colinfo->colnames. If there are USING columns, set_using_names() * already selected their names, so we can start the loop at the first * non-merged column. */ changed_any = false; for (i = list_length(colinfo->usingNames); i < noldcolumns; i++) { char *colname = colinfo->colnames[i]; char *real_colname; /* Ignore dropped column (only possible for non-merged column) */ if (colinfo->leftattnos[i] == 0 && colinfo->rightattnos[i] == 0) { Assert(colname == NULL); continue; } /* Get the child column name */ if (colinfo->leftattnos[i] > 0) real_colname = leftcolinfo->colnames[colinfo->leftattnos[i] - 1]; else if (colinfo->rightattnos[i] > 0) real_colname = rightcolinfo->colnames[colinfo->rightattnos[i] - 1]; else { /* We're joining system columns --- use eref name */ real_colname = strVal(list_nth(rte->eref->colnames, i)); } Assert(real_colname != NULL); /* In an unnamed join, just report child column names as-is */ if (rte->alias == NULL) { colinfo->colnames[i] = real_colname; continue; } /* If alias already assigned, that's what to use */ if (colname == NULL) { /* If user wrote an alias, prefer that over real column name */ if (rte->alias && i < list_length(rte->alias->colnames)) colname = strVal(list_nth(rte->alias->colnames, i)); else colname = real_colname; /* Unique-ify and insert into colinfo */ colname = make_colname_unique(colname, dpns, colinfo); colinfo->colnames[i] = colname; } /* Remember if any assigned aliases differ from "real" name */ if (!changed_any && strcmp(colname, real_colname) != 0) changed_any = true; } /* * Calculate number of columns the join would have if it were re-parsed * now, and create storage for the new_colnames and is_new_col arrays. * * Note: colname_is_unique will be consulting new_colnames[] during the * loops below, so its not-yet-filled entries must be zeroes. */ nnewcolumns = leftcolinfo->num_new_cols + rightcolinfo->num_new_cols - list_length(colinfo->usingNames); colinfo->num_new_cols = nnewcolumns; colinfo->new_colnames = (char **) palloc0(nnewcolumns * sizeof(char *)); colinfo->is_new_col = (bool *) palloc0(nnewcolumns * sizeof(bool)); /* * Generating the new_colnames array is a bit tricky since any new columns * added since parse time must be inserted in the right places. This code * must match the parser, which will order a join's columns as merged * columns first (in USING-clause order), then non-merged columns from the * left input (in attnum order), then non-merged columns from the right * input (ditto). If one of the inputs is itself a join, its columns will * be ordered according to the same rule, which means newly-added columns * might not be at the end. We can figure out what's what by consulting * the leftattnos and rightattnos arrays plus the input is_new_col arrays. * * In these loops, i indexes leftattnos/rightattnos (so it's join varattno * less one), j indexes new_colnames/is_new_col, and ic/jc have similar * meanings for the current child RTE. */ /* Handle merged columns; they are first and can't be new */ i = j = 0; while (i < noldcolumns && colinfo->leftattnos[i] != 0 && colinfo->rightattnos[i] != 0) { /* column name is already determined and known unique */ colinfo->new_colnames[j] = colinfo->colnames[i]; colinfo->is_new_col[j] = false; /* build bitmapsets of child attnums of merged columns */ if (colinfo->leftattnos[i] > 0) leftmerged = bms_add_member(leftmerged, colinfo->leftattnos[i]); if (colinfo->rightattnos[i] > 0) rightmerged = bms_add_member(rightmerged, colinfo->rightattnos[i]); i++, j++; } /* Handle non-merged left-child columns */ ic = 0; for (jc = 0; jc < leftcolinfo->num_new_cols; jc++) { char *child_colname = leftcolinfo->new_colnames[jc]; if (!leftcolinfo->is_new_col[jc]) { /* Advance ic to next non-dropped old column of left child */ while (ic < leftcolinfo->num_cols && leftcolinfo->colnames[ic] == NULL) ic++; Assert(ic < leftcolinfo->num_cols); ic++; /* If it is a merged column, we already processed it */ if (bms_is_member(ic, leftmerged)) continue; /* Else, advance i to the corresponding existing join column */ while (i < colinfo->num_cols && colinfo->colnames[i] == NULL) i++; Assert(i < colinfo->num_cols); Assert(ic == colinfo->leftattnos[i]); /* Use the already-assigned name of this column */ colinfo->new_colnames[j] = colinfo->colnames[i]; i++; } else { /* * Unique-ify the new child column name and assign, unless we're * in an unnamed join, in which case just copy */ if (rte->alias != NULL) { colinfo->new_colnames[j] = make_colname_unique(child_colname, dpns, colinfo); if (!changed_any && strcmp(colinfo->new_colnames[j], child_colname) != 0) changed_any = true; } else colinfo->new_colnames[j] = child_colname; } colinfo->is_new_col[j] = leftcolinfo->is_new_col[jc]; j++; } /* Handle non-merged right-child columns in exactly the same way */ ic = 0; for (jc = 0; jc < rightcolinfo->num_new_cols; jc++) { char *child_colname = rightcolinfo->new_colnames[jc]; if (!rightcolinfo->is_new_col[jc]) { /* Advance ic to next non-dropped old column of right child */ while (ic < rightcolinfo->num_cols && rightcolinfo->colnames[ic] == NULL) ic++; Assert(ic < rightcolinfo->num_cols); ic++; /* If it is a merged column, we already processed it */ if (bms_is_member(ic, rightmerged)) continue; /* Else, advance i to the corresponding existing join column */ while (i < colinfo->num_cols && colinfo->colnames[i] == NULL) i++; Assert(i < colinfo->num_cols); Assert(ic == colinfo->rightattnos[i]); /* Use the already-assigned name of this column */ colinfo->new_colnames[j] = colinfo->colnames[i]; i++; } else { /* * Unique-ify the new child column name and assign, unless we're * in an unnamed join, in which case just copy */ if (rte->alias != NULL) { colinfo->new_colnames[j] = make_colname_unique(child_colname, dpns, colinfo); if (!changed_any && strcmp(colinfo->new_colnames[j], child_colname) != 0) changed_any = true; } else colinfo->new_colnames[j] = child_colname; } colinfo->is_new_col[j] = rightcolinfo->is_new_col[jc]; j++; } /* Assert we processed the right number of columns */ #ifdef USE_ASSERT_CHECKING while (i < colinfo->num_cols && colinfo->colnames[i] == NULL) i++; Assert(i == colinfo->num_cols); Assert(j == nnewcolumns); #endif /* * For a named join, print column aliases if we changed any from the child * names. Unnamed joins cannot print aliases. */ if (rte->alias != NULL) colinfo->printaliases = changed_any; else colinfo->printaliases = false; } /* * colname_is_unique: is colname distinct from already-chosen column names? * * dpns is query-wide info, colinfo is for the column's RTE */ static bool colname_is_unique(char *colname, deparse_namespace *dpns, deparse_columns *colinfo) { int i; ListCell *lc; /* Check against already-assigned column aliases within RTE */ for (i = 0; i < colinfo->num_cols; i++) { char *oldname = colinfo->colnames[i]; if (oldname && strcmp(oldname, colname) == 0) return false; } /* * If we're building a new_colnames array, check that too (this will be * partially but not completely redundant with the previous checks) */ for (i = 0; i < colinfo->num_new_cols; i++) { char *oldname = colinfo->new_colnames[i]; if (oldname && strcmp(oldname, colname) == 0) return false; } /* Also check against USING-column names that must be globally unique */ foreach(lc, dpns->using_names) { char *oldname = (char *) lfirst(lc); if (strcmp(oldname, colname) == 0) return false; } /* Also check against names already assigned for parent-join USING cols */ foreach(lc, colinfo->parentUsing) { char *oldname = (char *) lfirst(lc); if (strcmp(oldname, colname) == 0) return false; } return true; } /* * make_colname_unique: modify colname if necessary to make it unique * * dpns is query-wide info, colinfo is for the column's RTE */ static char * make_colname_unique(char *colname, deparse_namespace *dpns, deparse_columns *colinfo) { /* * If the selected name isn't unique, append digits to make it so. For a * very long input name, we might have to truncate to stay within * NAMEDATALEN. */ if (!colname_is_unique(colname, dpns, colinfo)) { int colnamelen = strlen(colname); char *modname = (char *) palloc(colnamelen + 16); int i = 0; do { i++; for (;;) { /* * We avoid using %.*s here because it can misbehave if the * data is not valid in what libc thinks is the prevailing * encoding. */ memcpy(modname, colname, colnamelen); sprintf(modname + colnamelen, "_%d", i); if (strlen(modname) < NAMEDATALEN) break; /* drop chars from colname to keep all the digits */ colnamelen = pg_mbcliplen(colname, colnamelen, colnamelen - 1); } } while (!colname_is_unique(modname, dpns, colinfo)); colname = modname; } return colname; } /* * expand_colnames_array_to: make colinfo->colnames at least n items long * * Any added array entries are initialized to zero. */ static void expand_colnames_array_to(deparse_columns *colinfo, int n) { if (n > colinfo->num_cols) { if (colinfo->colnames == NULL) colinfo->colnames = (char **) palloc0(n * sizeof(char *)); else { colinfo->colnames = (char **) repalloc(colinfo->colnames, n * sizeof(char *)); memset(colinfo->colnames + colinfo->num_cols, 0, (n - colinfo->num_cols) * sizeof(char *)); } colinfo->num_cols = n; } } /* * identify_join_columns: figure out where columns of a join come from * * Fills the join-specific fields of the colinfo struct, except for * usingNames which is filled later. */ static void identify_join_columns(JoinExpr *j, RangeTblEntry *jrte, deparse_columns *colinfo) { int numjoincols; int i; ListCell *lc; /* Extract left/right child RT indexes */ if (IsA(j->larg, RangeTblRef)) colinfo->leftrti = ((RangeTblRef *) j->larg)->rtindex; else if (IsA(j->larg, JoinExpr)) colinfo->leftrti = ((JoinExpr *) j->larg)->rtindex; else elog(ERROR, "unrecognized node type in jointree: %d", (int) nodeTag(j->larg)); if (IsA(j->rarg, RangeTblRef)) colinfo->rightrti = ((RangeTblRef *) j->rarg)->rtindex; else if (IsA(j->rarg, JoinExpr)) colinfo->rightrti = ((JoinExpr *) j->rarg)->rtindex; else elog(ERROR, "unrecognized node type in jointree: %d", (int) nodeTag(j->rarg)); /* Assert children will be processed earlier than join in second pass */ Assert(colinfo->leftrti < j->rtindex); Assert(colinfo->rightrti < j->rtindex); /* Initialize result arrays with zeroes */ numjoincols = list_length(jrte->joinaliasvars); Assert(numjoincols == list_length(jrte->eref->colnames)); colinfo->leftattnos = (int *) palloc0(numjoincols * sizeof(int)); colinfo->rightattnos = (int *) palloc0(numjoincols * sizeof(int)); /* Scan the joinaliasvars list to identify simple column references */ i = 0; foreach(lc, jrte->joinaliasvars) { Var *aliasvar = (Var *) lfirst(lc); /* get rid of any implicit coercion above the Var */ aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar); if (aliasvar == NULL) { /* It's a dropped column; nothing to do here */ } else if (IsA(aliasvar, Var)) { Assert(aliasvar->varlevelsup == 0); Assert(aliasvar->varattno != 0); if (aliasvar->varno == colinfo->leftrti) colinfo->leftattnos[i] = aliasvar->varattno; else if (aliasvar->varno == colinfo->rightrti) colinfo->rightattnos[i] = aliasvar->varattno; else elog(ERROR, "unexpected varno %d in JOIN RTE", aliasvar->varno); } else if (IsA(aliasvar, CoalesceExpr)) { /* * It's a merged column in FULL JOIN USING. Ignore it for now and * let the code below identify the merged columns. */ } else elog(ERROR, "unrecognized node type in join alias vars: %d", (int) nodeTag(aliasvar)); i++; } /* * If there's a USING clause, deconstruct the join quals to identify the * merged columns. This is a tad painful but if we cannot rely on the * column names, there is no other representation of which columns were * joined by USING. (Unless the join type is FULL, we can't tell from the * joinaliasvars list which columns are merged.) Note: we assume that the * merged columns are the first output column(s) of the join. */ if (j->usingClause) { List *leftvars = NIL; List *rightvars = NIL; ListCell *lc2; /* Extract left- and right-side Vars from the qual expression */ flatten_join_using_qual(j->quals, &leftvars, &rightvars); Assert(list_length(leftvars) == list_length(j->usingClause)); Assert(list_length(rightvars) == list_length(j->usingClause)); /* Mark the output columns accordingly */ i = 0; forboth(lc, leftvars, lc2, rightvars) { Var *leftvar = (Var *) lfirst(lc); Var *rightvar = (Var *) lfirst(lc2); Assert(leftvar->varlevelsup == 0); Assert(leftvar->varattno != 0); if (leftvar->varno != colinfo->leftrti) elog(ERROR, "unexpected varno %d in JOIN USING qual", leftvar->varno); colinfo->leftattnos[i] = leftvar->varattno; Assert(rightvar->varlevelsup == 0); Assert(rightvar->varattno != 0); if (rightvar->varno != colinfo->rightrti) elog(ERROR, "unexpected varno %d in JOIN USING qual", rightvar->varno); colinfo->rightattnos[i] = rightvar->varattno; i++; } } } /* * flatten_join_using_qual: extract Vars being joined from a JOIN/USING qual * * We assume that transformJoinUsingClause won't have produced anything except * AND nodes, equality operator nodes, and possibly implicit coercions, and * that the AND node inputs match left-to-right with the original USING list. * * Caller must initialize the result lists to NIL. */ static void flatten_join_using_qual(Node *qual, List **leftvars, List **rightvars) { if (IsA(qual, BoolExpr)) { /* Handle AND nodes by recursion */ BoolExpr *b = (BoolExpr *) qual; ListCell *lc; Assert(b->boolop == AND_EXPR); foreach(lc, b->args) { flatten_join_using_qual((Node *) lfirst(lc), leftvars, rightvars); } } else if (IsA(qual, OpExpr)) { /* Otherwise we should have an equality operator */ OpExpr *op = (OpExpr *) qual; Var *var; if (list_length(op->args) != 2) elog(ERROR, "unexpected unary operator in JOIN/USING qual"); /* Arguments should be Vars with perhaps implicit coercions */ var = (Var *) strip_implicit_coercions((Node *) linitial(op->args)); if (!IsA(var, Var)) elog(ERROR, "unexpected node type in JOIN/USING qual: %d", (int) nodeTag(var)); *leftvars = lappend(*leftvars, var); var = (Var *) strip_implicit_coercions((Node *) lsecond(op->args)); if (!IsA(var, Var)) elog(ERROR, "unexpected node type in JOIN/USING qual: %d", (int) nodeTag(var)); *rightvars = lappend(*rightvars, var); } else { /* Perhaps we have an implicit coercion to boolean? */ Node *q = strip_implicit_coercions(qual); if (q != qual) flatten_join_using_qual(q, leftvars, rightvars); else elog(ERROR, "unexpected node type in JOIN/USING qual: %d", (int) nodeTag(qual)); } } /* * get_rtable_name: convenience function to get a previously assigned RTE alias * * The RTE must belong to the topmost namespace level in "context". */ static char * get_rtable_name(int rtindex, deparse_context *context) { deparse_namespace *dpns = (deparse_namespace *) linitial(context->namespaces); Assert(rtindex > 0 && rtindex <= list_length(dpns->rtable_names)); return (char *) list_nth(dpns->rtable_names, rtindex - 1); } /* * set_deparse_planstate: set up deparse_namespace to parse subexpressions * of a given PlanState node * * This sets the planstate, outer_planstate, inner_planstate, outer_tlist, * inner_tlist, and index_tlist fields. Caller is responsible for adjusting * the ancestors list if necessary. Note that the rtable and ctes fields do * not need to change when shifting attention to different plan nodes in a * single plan tree. */ static void set_deparse_planstate(deparse_namespace *dpns, PlanState *ps) { dpns->planstate = ps; /* * We special-case Append and MergeAppend to pretend that the first child * plan is the OUTER referent; we have to interpret OUTER Vars in their * tlists according to one of the children, and the first one is the most * natural choice. Likewise special-case ModifyTable to pretend that the * first child plan is the OUTER referent; this is to support RETURNING * lists containing references to non-target relations. */ if (IsA(ps, AppendState)) dpns->outer_planstate = ((AppendState *) ps)->appendplans[0]; else if (IsA(ps, MergeAppendState)) dpns->outer_planstate = ((MergeAppendState *) ps)->mergeplans[0]; else if (IsA(ps, ModifyTableState)) dpns->outer_planstate = ((ModifyTableState *) ps)->mt_plans[0]; else dpns->outer_planstate = outerPlanState(ps); if (dpns->outer_planstate) dpns->outer_tlist = dpns->outer_planstate->plan->targetlist; else dpns->outer_tlist = NIL; /* * For a SubqueryScan, pretend the subplan is INNER referent. (We don't * use OUTER because that could someday conflict with the normal meaning.) * Likewise, for a CteScan, pretend the subquery's plan is INNER referent. * For ON CONFLICT .. UPDATE we just need the inner tlist to point to the * excluded expression's tlist. (Similar to the SubqueryScan we don't want * to reuse OUTER, it's used for RETURNING in some modify table cases, * although not INSERT .. CONFLICT). */ if (IsA(ps, SubqueryScanState)) dpns->inner_planstate = ((SubqueryScanState *) ps)->subplan; else if (IsA(ps, CteScanState)) dpns->inner_planstate = ((CteScanState *) ps)->cteplanstate; else if (IsA(ps, ModifyTableState)) dpns->inner_planstate = ps; else dpns->inner_planstate = innerPlanState(ps); if (IsA(ps, ModifyTableState)) dpns->inner_tlist = ((ModifyTableState *) ps)->mt_excludedtlist; else if (dpns->inner_planstate) dpns->inner_tlist = dpns->inner_planstate->plan->targetlist; else dpns->inner_tlist = NIL; /* Set up referent for INDEX_VAR Vars, if needed */ if (IsA(ps->plan, IndexOnlyScan)) dpns->index_tlist = ((IndexOnlyScan *) ps->plan)->indextlist; else if (IsA(ps->plan, ForeignScan)) dpns->index_tlist = ((ForeignScan *) ps->plan)->fdw_scan_tlist; else if (IsA(ps->plan, CustomScan)) dpns->index_tlist = ((CustomScan *) ps->plan)->custom_scan_tlist; else dpns->index_tlist = NIL; } /* * push_child_plan: temporarily transfer deparsing attention to a child plan * * When expanding an OUTER_VAR or INNER_VAR reference, we must adjust the * deparse context in case the referenced expression itself uses * OUTER_VAR/INNER_VAR. We modify the top stack entry in-place to avoid * affecting levelsup issues (although in a Plan tree there really shouldn't * be any). * * Caller must provide a local deparse_namespace variable to save the * previous state for pop_child_plan. */ static void push_child_plan(deparse_namespace *dpns, PlanState *ps, deparse_namespace *save_dpns) { /* Save state for restoration later */ *save_dpns = *dpns; /* Link current plan node into ancestors list */ dpns->ancestors = lcons(dpns->planstate, dpns->ancestors); /* Set attention on selected child */ set_deparse_planstate(dpns, ps); } /* * pop_child_plan: undo the effects of push_child_plan */ static void pop_child_plan(deparse_namespace *dpns, deparse_namespace *save_dpns) { List *ancestors; /* Get rid of ancestors list cell added by push_child_plan */ ancestors = list_delete_first(dpns->ancestors); /* Restore fields changed by push_child_plan */ *dpns = *save_dpns; /* Make sure dpns->ancestors is right (may be unnecessary) */ dpns->ancestors = ancestors; } /* * push_ancestor_plan: temporarily transfer deparsing attention to an * ancestor plan * * When expanding a Param reference, we must adjust the deparse context * to match the plan node that contains the expression being printed; * otherwise we'd fail if that expression itself contains a Param or * OUTER_VAR/INNER_VAR/INDEX_VAR variable. * * The target ancestor is conveniently identified by the ListCell holding it * in dpns->ancestors. * * Caller must provide a local deparse_namespace variable to save the * previous state for pop_ancestor_plan. */ static void push_ancestor_plan(deparse_namespace *dpns, ListCell *ancestor_cell, deparse_namespace *save_dpns) { PlanState *ps = (PlanState *) lfirst(ancestor_cell); List *ancestors; /* Save state for restoration later */ *save_dpns = *dpns; /* Build a new ancestor list with just this node's ancestors */ ancestors = NIL; while ((ancestor_cell = lnext(ancestor_cell)) != NULL) ancestors = lappend(ancestors, lfirst(ancestor_cell)); dpns->ancestors = ancestors; /* Set attention on selected ancestor */ set_deparse_planstate(dpns, ps); } /* * pop_ancestor_plan: undo the effects of push_ancestor_plan */ static void pop_ancestor_plan(deparse_namespace *dpns, deparse_namespace *save_dpns) { /* Free the ancestor list made in push_ancestor_plan */ list_free(dpns->ancestors); /* Restore fields changed by push_ancestor_plan */ *dpns = *save_dpns; } /* ---------- * make_ruledef - reconstruct the CREATE RULE command * for a given pg_rewrite tuple * ---------- */ static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc, int prettyFlags) { char *rulename; char ev_type; Oid ev_class; bool is_instead; char *ev_qual; char *ev_action; List *actions = NIL; int fno; Datum dat; bool isnull; /* * Get the attribute values from the rules tuple */ fno = SPI_fnumber(rulettc, "rulename"); dat = SPI_getbinval(ruletup, rulettc, fno, &isnull); Assert(!isnull); rulename = NameStr(*(DatumGetName(dat))); fno = SPI_fnumber(rulettc, "ev_type"); dat = SPI_getbinval(ruletup, rulettc, fno, &isnull); Assert(!isnull); ev_type = DatumGetChar(dat); fno = SPI_fnumber(rulettc, "ev_class"); dat = SPI_getbinval(ruletup, rulettc, fno, &isnull); Assert(!isnull); ev_class = DatumGetObjectId(dat); fno = SPI_fnumber(rulettc, "is_instead"); dat = SPI_getbinval(ruletup, rulettc, fno, &isnull); Assert(!isnull); is_instead = DatumGetBool(dat); /* these could be nulls */ fno = SPI_fnumber(rulettc, "ev_qual"); ev_qual = SPI_getvalue(ruletup, rulettc, fno); fno = SPI_fnumber(rulettc, "ev_action"); ev_action = SPI_getvalue(ruletup, rulettc, fno); if (ev_action != NULL) actions = (List *) stringToNode(ev_action); /* * Build the rules definition text */ appendStringInfo(buf, "CREATE RULE %s AS", quote_identifier(rulename)); if (prettyFlags & PRETTYFLAG_INDENT) appendStringInfoString(buf, "\n ON "); else appendStringInfoString(buf, " ON "); /* The event the rule is fired for */ switch (ev_type) { case '1': appendStringInfoString(buf, "SELECT"); break; case '2': appendStringInfoString(buf, "UPDATE"); break; case '3': appendStringInfoString(buf, "INSERT"); break; case '4': appendStringInfoString(buf, "DELETE"); break; default: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("rule \"%s\" has unsupported event type %d", rulename, ev_type))); break; } /* The relation the rule is fired on */ appendStringInfo(buf, " TO %s", generate_relation_name(ev_class, NIL)); /* If the rule has an event qualification, add it */ if (ev_qual == NULL) ev_qual = ""; if (strlen(ev_qual) > 0 && strcmp(ev_qual, "<>") != 0) { Node *qual; Query *query; deparse_context context; deparse_namespace dpns; if (prettyFlags & PRETTYFLAG_INDENT) appendStringInfoString(buf, "\n "); appendStringInfoString(buf, " WHERE "); qual = stringToNode(ev_qual); /* * We need to make a context for recognizing any Vars in the qual * (which can only be references to OLD and NEW). Use the rtable of * the first query in the action list for this purpose. */ query = (Query *) linitial(actions); /* * If the action is INSERT...SELECT, OLD/NEW have been pushed down * into the SELECT, and that's what we need to look at. (Ugly kluge * ... try to fix this when we redesign querytrees.) */ query = getInsertSelectQuery(query, NULL); /* Must acquire locks right away; see notes in get_query_def() */ AcquireRewriteLocks(query, false, false); context.buf = buf; context.namespaces = list_make1(&dpns); context.windowClause = NIL; context.windowTList = NIL; context.varprefix = (list_length(query->rtable) != 1); context.prettyFlags = prettyFlags; context.wrapColumn = WRAP_COLUMN_DEFAULT; context.indentLevel = PRETTYINDENT_STD; context.special_exprkind = EXPR_KIND_NONE; set_deparse_for_query(&dpns, query, NIL); get_rule_expr(qual, &context, false); } appendStringInfoString(buf, " DO "); /* The INSTEAD keyword (if so) */ if (is_instead) appendStringInfoString(buf, "INSTEAD "); /* Finally the rules actions */ if (list_length(actions) > 1) { ListCell *action; Query *query; appendStringInfoChar(buf, '('); foreach(action, actions) { query = (Query *) lfirst(action); get_query_def(query, buf, NIL, NULL, prettyFlags, WRAP_COLUMN_DEFAULT, 0); if (prettyFlags) appendStringInfoString(buf, ";\n"); else appendStringInfoString(buf, "; "); } appendStringInfoString(buf, ");"); } else if (list_length(actions) == 0) { appendStringInfoString(buf, "NOTHING;"); } else { Query *query; query = (Query *) linitial(actions); get_query_def(query, buf, NIL, NULL, prettyFlags, WRAP_COLUMN_DEFAULT, 0); appendStringInfoChar(buf, ';'); } } /* ---------- * make_viewdef - reconstruct the SELECT part of a * view rewrite rule * ---------- */ static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc, int prettyFlags, int wrapColumn) { Query *query; char ev_type; Oid ev_class; bool is_instead; char *ev_qual; char *ev_action; List *actions = NIL; Relation ev_relation; int fno; bool isnull; /* * Get the attribute values from the rules tuple */ fno = SPI_fnumber(rulettc, "ev_type"); ev_type = (char) SPI_getbinval(ruletup, rulettc, fno, &isnull); fno = SPI_fnumber(rulettc, "ev_class"); ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull); fno = SPI_fnumber(rulettc, "is_instead"); is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull); fno = SPI_fnumber(rulettc, "ev_qual"); ev_qual = SPI_getvalue(ruletup, rulettc, fno); fno = SPI_fnumber(rulettc, "ev_action"); ev_action = SPI_getvalue(ruletup, rulettc, fno); if (ev_action != NULL) actions = (List *) stringToNode(ev_action); if (list_length(actions) != 1) { appendStringInfoString(buf, "Not a view"); return; } query = (Query *) linitial(actions); if (ev_type != '1' || !is_instead || strcmp(ev_qual, "<>") != 0 || query->commandType != CMD_SELECT) { appendStringInfoString(buf, "Not a view"); return; } ev_relation = heap_open(ev_class, AccessShareLock); get_query_def(query, buf, NIL, RelationGetDescr(ev_relation), prettyFlags, wrapColumn, 0); appendStringInfoChar(buf, ';'); heap_close(ev_relation, AccessShareLock); } /* ---------- * get_query_def - Parse back one query parsetree * * If resultDesc is not NULL, then it is the output tuple descriptor for * the view represented by a SELECT query. * ---------- */ static void get_query_def(Query *query, StringInfo buf, List *parentnamespace, TupleDesc resultDesc, int prettyFlags, int wrapColumn, int startIndent) { deparse_context context; deparse_namespace dpns; /* Guard against excessively long or deeply-nested queries */ CHECK_FOR_INTERRUPTS(); check_stack_depth(); /* * Before we begin to examine the query, acquire locks on referenced * relations, and fix up deleted columns in JOIN RTEs. This ensures * consistent results. Note we assume it's OK to scribble on the passed * querytree! * * We are only deparsing the query (we are not about to execute it), so we * only need AccessShareLock on the relations it mentions. */ AcquireRewriteLocks(query, false, false); context.buf = buf; context.namespaces = lcons(&dpns, list_copy(parentnamespace)); context.windowClause = NIL; context.windowTList = NIL; context.varprefix = (parentnamespace != NIL || list_length(query->rtable) != 1); context.prettyFlags = prettyFlags; context.wrapColumn = wrapColumn; context.indentLevel = startIndent; context.special_exprkind = EXPR_KIND_NONE; set_deparse_for_query(&dpns, query, parentnamespace); switch (query->commandType) { case CMD_SELECT: get_select_query_def(query, &context, resultDesc); break; case CMD_UPDATE: get_update_query_def(query, &context); break; case CMD_INSERT: get_insert_query_def(query, &context); break; case CMD_DELETE: get_delete_query_def(query, &context); break; case CMD_NOTHING: appendStringInfoString(buf, "NOTHING"); break; case CMD_UTILITY: get_utility_query_def(query, &context); break; default: elog(ERROR, "unrecognized query command type: %d", query->commandType); break; } } /* ---------- * get_values_def - Parse back a VALUES list * ---------- */ static void get_values_def(List *values_lists, deparse_context *context) { StringInfo buf = context->buf; bool first_list = true; ListCell *vtl; appendStringInfoString(buf, "VALUES "); foreach(vtl, values_lists) { List *sublist = (List *) lfirst(vtl); bool first_col = true; ListCell *lc; if (first_list) first_list = false; else appendStringInfoString(buf, ", "); appendStringInfoChar(buf, '('); foreach(lc, sublist) { Node *col = (Node *) lfirst(lc); if (first_col) first_col = false; else appendStringInfoChar(buf, ','); /* * Strip any top-level nodes representing indirection assignments, * then print the result. Whole-row Vars need special treatment. */ get_rule_expr_toplevel(processIndirection(col, context, false), context, false); } appendStringInfoChar(buf, ')'); } } /* ---------- * get_with_clause - Parse back a WITH clause * ---------- */ static void get_with_clause(Query *query, deparse_context *context) { StringInfo buf = context->buf; const char *sep; ListCell *l; if (query->cteList == NIL) return; if (PRETTY_INDENT(context)) { context->indentLevel += PRETTYINDENT_STD; appendStringInfoChar(buf, ' '); } if (query->hasRecursive) sep = "WITH RECURSIVE "; else sep = "WITH "; foreach(l, query->cteList) { CommonTableExpr *cte = (CommonTableExpr *) lfirst(l); appendStringInfoString(buf, sep); appendStringInfoString(buf, quote_identifier(cte->ctename)); if (cte->aliascolnames) { bool first = true; ListCell *col; appendStringInfoChar(buf, '('); foreach(col, cte->aliascolnames) { if (first) first = false; else appendStringInfoString(buf, ", "); appendStringInfoString(buf, quote_identifier(strVal(lfirst(col)))); } appendStringInfoChar(buf, ')'); } appendStringInfoString(buf, " AS ("); if (PRETTY_INDENT(context)) appendContextKeyword(context, "", 0, 0, 0); get_query_def((Query *) cte->ctequery, buf, context->namespaces, NULL, context->prettyFlags, context->wrapColumn, context->indentLevel); if (PRETTY_INDENT(context)) appendContextKeyword(context, "", 0, 0, 0); appendStringInfoChar(buf, ')'); sep = ", "; } if (PRETTY_INDENT(context)) { context->indentLevel -= PRETTYINDENT_STD; appendContextKeyword(context, "", 0, 0, 0); } else appendStringInfoChar(buf, ' '); } /* ---------- * get_select_query_def - Parse back a SELECT parsetree * ---------- */ static void get_select_query_def(Query *query, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; List *save_windowclause; List *save_windowtlist; bool force_colno; ListCell *l; /* Insert the WITH clause if given */ get_with_clause(query, context); /* Set up context for possible window functions */ save_windowclause = context->windowClause; context->windowClause = query->windowClause; save_windowtlist = context->windowTList; context->windowTList = query->targetList; /* * If the Query node has a setOperations tree, then it's the top level of * a UNION/INTERSECT/EXCEPT query; only the WITH, ORDER BY and LIMIT * fields are interesting in the top query itself. */ if (query->setOperations) { get_setop_query(query->setOperations, query, context, resultDesc); /* ORDER BY clauses must be simple in this case */ force_colno = true; } else { get_basic_select_query(query, context, resultDesc); force_colno = false; } /* Add the ORDER BY clause if given */ if (query->sortClause != NIL) { appendContextKeyword(context, " ORDER BY ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_orderby(query->sortClause, query->targetList, force_colno, context); } /* Add the LIMIT clause if given */ if (query->limitOffset != NULL) { appendContextKeyword(context, " OFFSET ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); get_rule_expr(query->limitOffset, context, false); } if (query->limitCount != NULL) { appendContextKeyword(context, " LIMIT ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); if (IsA(query->limitCount, Const) && ((Const *) query->limitCount)->constisnull) appendStringInfoString(buf, "ALL"); else get_rule_expr(query->limitCount, context, false); } /* Add FOR [KEY] UPDATE/SHARE clauses if present */ if (query->hasForUpdate) { foreach(l, query->rowMarks) { RowMarkClause *rc = (RowMarkClause *) lfirst(l); /* don't print implicit clauses */ if (rc->pushedDown) continue; switch (rc->strength) { case LCS_NONE: /* we intentionally throw an error for LCS_NONE */ elog(ERROR, "unrecognized LockClauseStrength %d", (int) rc->strength); break; case LCS_FORKEYSHARE: appendContextKeyword(context, " FOR KEY SHARE", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); break; case LCS_FORSHARE: appendContextKeyword(context, " FOR SHARE", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); break; case LCS_FORNOKEYUPDATE: appendContextKeyword(context, " FOR NO KEY UPDATE", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); break; case LCS_FORUPDATE: appendContextKeyword(context, " FOR UPDATE", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); break; } appendStringInfo(buf, " OF %s", quote_identifier(get_rtable_name(rc->rti, context))); if (rc->waitPolicy == LockWaitError) appendStringInfoString(buf, " NOWAIT"); else if (rc->waitPolicy == LockWaitSkip) appendStringInfoString(buf, " SKIP LOCKED"); } } context->windowClause = save_windowclause; context->windowTList = save_windowtlist; } /* * Detect whether query looks like SELECT ... FROM VALUES(); * if so, return the VALUES RTE. Otherwise return NULL. */ static RangeTblEntry * get_simple_values_rte(Query *query) { RangeTblEntry *result = NULL; ListCell *lc; /* * We want to return TRUE even if the Query also contains OLD or NEW rule * RTEs. So the idea is to scan the rtable and see if there is only one * inFromCl RTE that is a VALUES RTE. */ foreach(lc, query->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); if (rte->rtekind == RTE_VALUES && rte->inFromCl) { if (result) return NULL; /* multiple VALUES (probably not possible) */ result = rte; } else if (rte->rtekind == RTE_RELATION && !rte->inFromCl) continue; /* ignore rule entries */ else return NULL; /* something else -> not simple VALUES */ } /* * We don't need to check the targetlist in any great detail, because * parser/analyze.c will never generate a "bare" VALUES RTE --- they only * appear inside auto-generated sub-queries with very restricted * structure. However, DefineView might have modified the tlist by * injecting new column aliases; so compare tlist resnames against the * RTE's names to detect that. */ if (result) { ListCell *lcn; if (list_length(query->targetList) != list_length(result->eref->colnames)) return NULL; /* this probably cannot happen */ forboth(lc, query->targetList, lcn, result->eref->colnames) { TargetEntry *tle = (TargetEntry *) lfirst(lc); char *cname = strVal(lfirst(lcn)); if (tle->resjunk) return NULL; /* this probably cannot happen */ if (tle->resname == NULL || strcmp(tle->resname, cname) != 0) return NULL; /* column name has been changed */ } } return result; } static void get_basic_select_query(Query *query, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; RangeTblEntry *values_rte; char *sep; ListCell *l; if (PRETTY_INDENT(context)) { context->indentLevel += PRETTYINDENT_STD; appendStringInfoChar(buf, ' '); } /* * If the query looks like SELECT * FROM (VALUES ...), then print just the * VALUES part. This reverses what transformValuesClause() did at parse * time. */ values_rte = get_simple_values_rte(query); if (values_rte) { get_values_def(values_rte->values_lists, context); return; } /* * Build up the query string - first we say SELECT */ appendStringInfoString(buf, "SELECT"); /* Add the DISTINCT clause if given */ if (query->distinctClause != NIL) { if (query->hasDistinctOn) { appendStringInfoString(buf, " DISTINCT ON ("); sep = ""; foreach(l, query->distinctClause) { SortGroupClause *srt = (SortGroupClause *) lfirst(l); appendStringInfoString(buf, sep); get_rule_sortgroupclause(srt->tleSortGroupRef, query->targetList, false, context); sep = ", "; } appendStringInfoChar(buf, ')'); } else appendStringInfoString(buf, " DISTINCT"); } /* Then we tell what to select (the targetlist) */ get_target_list(query->targetList, context, resultDesc); /* Add the FROM clause if needed */ get_from_clause(query, " FROM ", context); /* Add the WHERE clause if given */ if (query->jointree->quals != NULL) { appendContextKeyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_expr(query->jointree->quals, context, false); } /* Add the GROUP BY clause if given */ if (query->groupClause != NULL || query->groupingSets != NULL) { ParseExprKind save_exprkind; appendContextKeyword(context, " GROUP BY ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); save_exprkind = context->special_exprkind; context->special_exprkind = EXPR_KIND_GROUP_BY; if (query->groupingSets == NIL) { sep = ""; foreach(l, query->groupClause) { SortGroupClause *grp = (SortGroupClause *) lfirst(l); appendStringInfoString(buf, sep); get_rule_sortgroupclause(grp->tleSortGroupRef, query->targetList, false, context); sep = ", "; } } else { sep = ""; foreach(l, query->groupingSets) { GroupingSet *grp = lfirst(l); appendStringInfoString(buf, sep); get_rule_groupingset(grp, query->targetList, true, context); sep = ", "; } } context->special_exprkind = save_exprkind; } /* Add the HAVING clause if given */ if (query->havingQual != NULL) { appendContextKeyword(context, " HAVING ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); get_rule_expr(query->havingQual, context, false); } /* Add the WINDOW clause if needed */ if (query->windowClause != NIL) get_rule_windowclause(query, context); } /* ---------- * get_target_list - Parse back a SELECT target list * * This is also used for RETURNING lists in INSERT/UPDATE/DELETE. * ---------- */ static void get_target_list(List *targetList, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; StringInfoData targetbuf; bool last_was_multiline = false; char *sep; int colno; ListCell *l; /* we use targetbuf to hold each TLE's text temporarily */ initStringInfo(&targetbuf); sep = " "; colno = 0; foreach(l, targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); char *colname; char *attname; if (tle->resjunk) continue; /* ignore junk entries */ appendStringInfoString(buf, sep); sep = ", "; colno++; /* * Put the new field text into targetbuf so we can decide after we've * got it whether or not it needs to go on a new line. */ resetStringInfo(&targetbuf); context->buf = &targetbuf; /* * We special-case Var nodes rather than using get_rule_expr. This is * needed because get_rule_expr will display a whole-row Var as * "foo.*", which is the preferred notation in most contexts, but at * the top level of a SELECT list it's not right (the parser will * expand that notation into multiple columns, yielding behavior * different from a whole-row Var). We need to call get_variable * directly so that we can tell it to do the right thing, and so that * we can get the attribute name which is the default AS label. */ if (tle->expr && (IsA(tle->expr, Var))) { attname = get_variable((Var *) tle->expr, 0, true, context); } else { get_rule_expr((Node *) tle->expr, context, true); /* We'll show the AS name unless it's this: */ attname = "?column?"; } /* * Figure out what the result column should be called. In the context * of a view, use the view's tuple descriptor (so as to pick up the * effects of any column RENAME that's been done on the view). * Otherwise, just use what we can find in the TLE. */ if (resultDesc && colno <= resultDesc->natts) colname = NameStr(resultDesc->attrs[colno - 1]->attname); else colname = tle->resname; /* Show AS unless the column's name is correct as-is */ if (colname) /* resname could be NULL */ { if (attname == NULL || strcmp(attname, colname) != 0) appendStringInfo(&targetbuf, " AS %s", quote_identifier(colname)); } /* Restore context's output buffer */ context->buf = buf; /* Consider line-wrapping if enabled */ if (PRETTY_INDENT(context) && context->wrapColumn >= 0) { int leading_nl_pos; /* Does the new field start with a new line? */ if (targetbuf.len > 0 && targetbuf.data[0] == '\n') leading_nl_pos = 0; else leading_nl_pos = -1; /* If so, we shouldn't add anything */ if (leading_nl_pos >= 0) { /* instead, remove any trailing spaces currently in buf */ removeStringInfoSpaces(buf); } else { char *trailing_nl; /* Locate the start of the current line in the output buffer */ trailing_nl = strrchr(buf->data, '\n'); if (trailing_nl == NULL) trailing_nl = buf->data; else trailing_nl++; /* * Add a newline, plus some indentation, if the new field is * not the first and either the new field would cause an * overflow or the last field used more than one line. */ if (colno > 1 && ((strlen(trailing_nl) + targetbuf.len > context->wrapColumn) || last_was_multiline)) appendContextKeyword(context, "", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_VAR); } /* Remember this field's multiline status for next iteration */ last_was_multiline = (strchr(targetbuf.data + leading_nl_pos + 1, '\n') != NULL); } /* Add the new field */ appendStringInfoString(buf, targetbuf.data); } /* clean up */ pfree(targetbuf.data); } static void get_setop_query(Node *setOp, Query *query, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; bool need_paren; /* Guard against excessively long or deeply-nested queries */ CHECK_FOR_INTERRUPTS(); check_stack_depth(); if (IsA(setOp, RangeTblRef)) { RangeTblRef *rtr = (RangeTblRef *) setOp; RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable); Query *subquery = rte->subquery; Assert(subquery != NULL); Assert(subquery->setOperations == NULL); /* Need parens if WITH, ORDER BY, FOR UPDATE, or LIMIT; see gram.y */ need_paren = (subquery->cteList || subquery->sortClause || subquery->rowMarks || subquery->limitOffset || subquery->limitCount); if (need_paren) appendStringInfoChar(buf, '('); get_query_def(subquery, buf, context->namespaces, resultDesc, context->prettyFlags, context->wrapColumn, context->indentLevel); if (need_paren) appendStringInfoChar(buf, ')'); } else if (IsA(setOp, SetOperationStmt)) { SetOperationStmt *op = (SetOperationStmt *) setOp; int subindent; /* * We force parens when nesting two SetOperationStmts, except when the * lefthand input is another setop of the same kind. Syntactically, * we could omit parens in rather more cases, but it seems best to use * parens to flag cases where the setop operator changes. If we use * parens, we also increase the indentation level for the child query. * * There are some cases in which parens are needed around a leaf query * too, but those are more easily handled at the next level down (see * code above). */ if (IsA(op->larg, SetOperationStmt)) { SetOperationStmt *lop = (SetOperationStmt *) op->larg; if (op->op == lop->op && op->all == lop->all) need_paren = false; else need_paren = true; } else need_paren = false; if (need_paren) { appendStringInfoChar(buf, '('); subindent = PRETTYINDENT_STD; appendContextKeyword(context, "", subindent, 0, 0); } else subindent = 0; get_setop_query(op->larg, query, context, resultDesc); if (need_paren) appendContextKeyword(context, ") ", -subindent, 0, 0); else if (PRETTY_INDENT(context)) appendContextKeyword(context, "", -subindent, 0, 0); else appendStringInfoChar(buf, ' '); switch (op->op) { case SETOP_UNION: appendStringInfoString(buf, "UNION "); break; case SETOP_INTERSECT: appendStringInfoString(buf, "INTERSECT "); break; case SETOP_EXCEPT: appendStringInfoString(buf, "EXCEPT "); break; default: elog(ERROR, "unrecognized set op: %d", (int) op->op); } if (op->all) appendStringInfoString(buf, "ALL "); /* Always parenthesize if RHS is another setop */ need_paren = IsA(op->rarg, SetOperationStmt); /* * The indentation code here is deliberately a bit different from that * for the lefthand input, because we want the line breaks in * different places. */ if (need_paren) { appendStringInfoChar(buf, '('); subindent = PRETTYINDENT_STD; } else subindent = 0; appendContextKeyword(context, "", subindent, 0, 0); get_setop_query(op->rarg, query, context, resultDesc); if (PRETTY_INDENT(context)) context->indentLevel -= subindent; if (need_paren) appendContextKeyword(context, ")", 0, 0, 0); } else { elog(ERROR, "unrecognized node type: %d", (int) nodeTag(setOp)); } } /* * Display a sort/group clause. * * Also returns the expression tree, so caller need not find it again. */ static Node * get_rule_sortgroupclause(Index ref, List *tlist, bool force_colno, deparse_context *context) { StringInfo buf = context->buf; TargetEntry *tle; Node *expr; tle = get_sortgroupref_tle(ref, tlist); expr = (Node *) tle->expr; /* * Use column-number form if requested by caller. Otherwise, if * expression is a constant, force it to be dumped with an explicit cast * as decoration --- this is because a simple integer constant is * ambiguous (and will be misinterpreted by findTargetlistEntry()) if we * dump it without any decoration. If it's anything more complex than a * simple Var, then force extra parens around it, to ensure it can't be * misinterpreted as a cube() or rollup() construct. */ if (force_colno) { Assert(!tle->resjunk); appendStringInfo(buf, "%d", tle->resno); } else if (expr && IsA(expr, Const)) get_const_expr((Const *) expr, context, 1); else if (!expr || IsA(expr, Var)) get_rule_expr(expr, context, true); else { /* * We must force parens for function-like expressions even if * PRETTY_PAREN is off, since those are the ones in danger of * misparsing. For other expressions we need to force them only if * PRETTY_PAREN is on, since otherwise the expression will output them * itself. (We can't skip the parens.) */ bool need_paren = (PRETTY_PAREN(context) || IsA(expr, FuncExpr) ||IsA(expr, Aggref) ||IsA(expr, WindowFunc)); if (need_paren) appendStringInfoString(context->buf, "("); get_rule_expr(expr, context, true); if (need_paren) appendStringInfoString(context->buf, ")"); } return expr; } /* * Display a GroupingSet */ static void get_rule_groupingset(GroupingSet *gset, List *targetlist, bool omit_parens, deparse_context *context) { ListCell *l; StringInfo buf = context->buf; bool omit_child_parens = true; char *sep = ""; switch (gset->kind) { case GROUPING_SET_EMPTY: appendStringInfoString(buf, "()"); return; case GROUPING_SET_SIMPLE: { if (!omit_parens || list_length(gset->content) != 1) appendStringInfoString(buf, "("); foreach(l, gset->content) { Index ref = lfirst_int(l); appendStringInfoString(buf, sep); get_rule_sortgroupclause(ref, targetlist, false, context); sep = ", "; } if (!omit_parens || list_length(gset->content) != 1) appendStringInfoString(buf, ")"); } return; case GROUPING_SET_ROLLUP: appendStringInfoString(buf, "ROLLUP("); break; case GROUPING_SET_CUBE: appendStringInfoString(buf, "CUBE("); break; case GROUPING_SET_SETS: appendStringInfoString(buf, "GROUPING SETS ("); omit_child_parens = false; break; } foreach(l, gset->content) { appendStringInfoString(buf, sep); get_rule_groupingset(lfirst(l), targetlist, omit_child_parens, context); sep = ", "; } appendStringInfoString(buf, ")"); } /* * Display an ORDER BY list. */ static void get_rule_orderby(List *orderList, List *targetList, bool force_colno, deparse_context *context) { StringInfo buf = context->buf; const char *sep; ListCell *l; sep = ""; foreach(l, orderList) { SortGroupClause *srt = (SortGroupClause *) lfirst(l); Node *sortexpr; Oid sortcoltype; TypeCacheEntry *typentry; appendStringInfoString(buf, sep); sortexpr = get_rule_sortgroupclause(srt->tleSortGroupRef, targetList, force_colno, context); sortcoltype = exprType(sortexpr); /* See whether operator is default < or > for datatype */ typentry = lookup_type_cache(sortcoltype, TYPECACHE_LT_OPR | TYPECACHE_GT_OPR); if (srt->sortop == typentry->lt_opr) { /* ASC is default, so emit nothing for it */ if (srt->nulls_first) appendStringInfoString(buf, " NULLS FIRST"); } else if (srt->sortop == typentry->gt_opr) { appendStringInfoString(buf, " DESC"); /* DESC defaults to NULLS FIRST */ if (!srt->nulls_first) appendStringInfoString(buf, " NULLS LAST"); } else { appendStringInfo(buf, " USING %s", generate_operator_name(srt->sortop, sortcoltype, sortcoltype)); /* be specific to eliminate ambiguity */ if (srt->nulls_first) appendStringInfoString(buf, " NULLS FIRST"); else appendStringInfoString(buf, " NULLS LAST"); } sep = ", "; } } /* * Display a WINDOW clause. * * Note that the windowClause list might contain only anonymous window * specifications, in which case we should print nothing here. */ static void get_rule_windowclause(Query *query, deparse_context *context) { StringInfo buf = context->buf; const char *sep; ListCell *l; sep = NULL; foreach(l, query->windowClause) { WindowClause *wc = (WindowClause *) lfirst(l); if (wc->name == NULL) continue; /* ignore anonymous windows */ if (sep == NULL) appendContextKeyword(context, " WINDOW ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); else appendStringInfoString(buf, sep); appendStringInfo(buf, "%s AS ", quote_identifier(wc->name)); get_rule_windowspec(wc, query->targetList, context); sep = ", "; } } /* * Display a window definition */ static void get_rule_windowspec(WindowClause *wc, List *targetList, deparse_context *context) { StringInfo buf = context->buf; bool needspace = false; const char *sep; ListCell *l; appendStringInfoChar(buf, '('); if (wc->refname) { appendStringInfoString(buf, quote_identifier(wc->refname)); needspace = true; } /* partition clauses are always inherited, so only print if no refname */ if (wc->partitionClause && !wc->refname) { if (needspace) appendStringInfoChar(buf, ' '); appendStringInfoString(buf, "PARTITION BY "); sep = ""; foreach(l, wc->partitionClause) { SortGroupClause *grp = (SortGroupClause *) lfirst(l); appendStringInfoString(buf, sep); get_rule_sortgroupclause(grp->tleSortGroupRef, targetList, false, context); sep = ", "; } needspace = true; } /* print ordering clause only if not inherited */ if (wc->orderClause && !wc->copiedOrder) { if (needspace) appendStringInfoChar(buf, ' '); appendStringInfoString(buf, "ORDER BY "); get_rule_orderby(wc->orderClause, targetList, false, context); needspace = true; } /* framing clause is never inherited, so print unless it's default */ if (wc->frameOptions & FRAMEOPTION_NONDEFAULT) { if (needspace) appendStringInfoChar(buf, ' '); if (wc->frameOptions & FRAMEOPTION_RANGE) appendStringInfoString(buf, "RANGE "); else if (wc->frameOptions & FRAMEOPTION_ROWS) appendStringInfoString(buf, "ROWS "); else Assert(false); if (wc->frameOptions & FRAMEOPTION_BETWEEN) appendStringInfoString(buf, "BETWEEN "); if (wc->frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) appendStringInfoString(buf, "UNBOUNDED PRECEDING "); else if (wc->frameOptions & FRAMEOPTION_START_CURRENT_ROW) appendStringInfoString(buf, "CURRENT ROW "); else if (wc->frameOptions & FRAMEOPTION_START_VALUE) { get_rule_expr(wc->startOffset, context, false); if (wc->frameOptions & FRAMEOPTION_START_VALUE_PRECEDING) appendStringInfoString(buf, " PRECEDING "); else if (wc->frameOptions & FRAMEOPTION_START_VALUE_FOLLOWING) appendStringInfoString(buf, " FOLLOWING "); else Assert(false); } else Assert(false); if (wc->frameOptions & FRAMEOPTION_BETWEEN) { appendStringInfoString(buf, "AND "); if (wc->frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING) appendStringInfoString(buf, "UNBOUNDED FOLLOWING "); else if (wc->frameOptions & FRAMEOPTION_END_CURRENT_ROW) appendStringInfoString(buf, "CURRENT ROW "); else if (wc->frameOptions & FRAMEOPTION_END_VALUE) { get_rule_expr(wc->endOffset, context, false); if (wc->frameOptions & FRAMEOPTION_END_VALUE_PRECEDING) appendStringInfoString(buf, " PRECEDING "); else if (wc->frameOptions & FRAMEOPTION_END_VALUE_FOLLOWING) appendStringInfoString(buf, " FOLLOWING "); else Assert(false); } else Assert(false); } /* we will now have a trailing space; remove it */ buf->len--; } appendStringInfoChar(buf, ')'); } /* ---------- * get_insert_query_def - Parse back an INSERT parsetree * ---------- */ static void get_insert_query_def(Query *query, deparse_context *context) { StringInfo buf = context->buf; RangeTblEntry *select_rte = NULL; RangeTblEntry *values_rte = NULL; RangeTblEntry *rte; char *sep; ListCell *values_cell; ListCell *l; List *strippedexprs; /* Insert the WITH clause if given */ get_with_clause(query, context); /* * If it's an INSERT ... SELECT or multi-row VALUES, there will be a * single RTE for the SELECT or VALUES. Plain VALUES has neither. */ foreach(l, query->rtable) { rte = (RangeTblEntry *) lfirst(l); if (rte->rtekind == RTE_SUBQUERY) { if (select_rte) elog(ERROR, "too many subquery RTEs in INSERT"); select_rte = rte; } if (rte->rtekind == RTE_VALUES) { if (values_rte) elog(ERROR, "too many values RTEs in INSERT"); values_rte = rte; } } if (select_rte && values_rte) elog(ERROR, "both subquery and values RTEs in INSERT"); /* * Start the query with INSERT INTO relname */ rte = rt_fetch(query->resultRelation, query->rtable); Assert(rte->rtekind == RTE_RELATION); if (PRETTY_INDENT(context)) { context->indentLevel += PRETTYINDENT_STD; appendStringInfoChar(buf, ' '); } appendStringInfo(buf, "INSERT INTO %s ", generate_relation_name(rte->relid, NIL)); /* INSERT requires AS keyword for target alias */ if (rte->alias != NULL) appendStringInfo(buf, "AS %s ", quote_identifier(rte->alias->aliasname)); /* * Add the insert-column-names list. To handle indirection properly, we * need to look for indirection nodes in the top targetlist (if it's * INSERT ... SELECT or INSERT ... single VALUES), or in the first * expression list of the VALUES RTE (if it's INSERT ... multi VALUES). We * assume that all the expression lists will have similar indirection in * the latter case. */ if (values_rte) values_cell = list_head((List *) linitial(values_rte->values_lists)); else values_cell = NULL; strippedexprs = NIL; sep = ""; if (query->targetList) appendStringInfoChar(buf, '('); foreach(l, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resjunk) continue; /* ignore junk entries */ appendStringInfoString(buf, sep); sep = ", "; /* * Put out name of target column; look in the catalogs, not at * tle->resname, since resname will fail to track RENAME. */ appendStringInfoString(buf, quote_identifier(get_relid_attribute_name(rte->relid, tle->resno))); /* * Print any indirection needed (subfields or subscripts), and strip * off the top-level nodes representing the indirection assignments. */ if (values_cell) { /* we discard the stripped expression in this case */ processIndirection((Node *) lfirst(values_cell), context, true); values_cell = lnext(values_cell); } else { /* we keep a list of the stripped expressions in this case */ strippedexprs = lappend(strippedexprs, processIndirection((Node *) tle->expr, context, true)); } } if (query->targetList) appendStringInfoString(buf, ") "); if (select_rte) { /* Add the SELECT */ get_query_def(select_rte->subquery, buf, NIL, NULL, context->prettyFlags, context->wrapColumn, context->indentLevel); } else if (values_rte) { /* Add the multi-VALUES expression lists */ get_values_def(values_rte->values_lists, context); } else if (strippedexprs) { /* Add the single-VALUES expression list */ appendContextKeyword(context, "VALUES (", -PRETTYINDENT_STD, PRETTYINDENT_STD, 2); get_rule_expr((Node *) strippedexprs, context, false); appendStringInfoChar(buf, ')'); } else { /* No expressions, so it must be DEFAULT VALUES */ appendStringInfoString(buf, "DEFAULT VALUES"); } /* Add ON CONFLICT if present */ if (query->onConflict) { OnConflictExpr *confl = query->onConflict; appendStringInfoString(buf, " ON CONFLICT"); if (confl->arbiterElems) { /* Add the single-VALUES expression list */ appendStringInfoChar(buf, '('); get_rule_expr((Node *) confl->arbiterElems, context, false); appendStringInfoChar(buf, ')'); /* Add a WHERE clause (for partial indexes) if given */ if (confl->arbiterWhere != NULL) { appendContextKeyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_expr(confl->arbiterWhere, context, false); } } else if (confl->constraint != InvalidOid) { char *constraint = get_constraint_name(confl->constraint); appendStringInfo(buf, " ON CONSTRAINT %s", quote_qualified_identifier(NULL, constraint)); } if (confl->action == ONCONFLICT_NOTHING) { appendStringInfoString(buf, " DO NOTHING"); } else { appendStringInfoString(buf, " DO UPDATE SET "); /* Deparse targetlist */ get_update_query_targetlist_def(query, confl->onConflictSet, context, rte); /* Add a WHERE clause if given */ if (confl->onConflictWhere != NULL) { appendContextKeyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_expr(confl->onConflictWhere, context, false); } } } /* Add RETURNING if present */ if (query->returningList) { appendContextKeyword(context, " RETURNING", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_target_list(query->returningList, context, NULL); } } /* ---------- * get_update_query_def - Parse back an UPDATE parsetree * ---------- */ static void get_update_query_def(Query *query, deparse_context *context) { StringInfo buf = context->buf; RangeTblEntry *rte; /* Insert the WITH clause if given */ get_with_clause(query, context); /* * Start the query with UPDATE relname SET */ rte = rt_fetch(query->resultRelation, query->rtable); Assert(rte->rtekind == RTE_RELATION); if (PRETTY_INDENT(context)) { appendStringInfoChar(buf, ' '); context->indentLevel += PRETTYINDENT_STD; } appendStringInfo(buf, "UPDATE %s%s", only_marker(rte), generate_relation_name(rte->relid, NIL)); if (rte->alias != NULL) appendStringInfo(buf, " %s", quote_identifier(rte->alias->aliasname)); appendStringInfoString(buf, " SET "); /* Deparse targetlist */ get_update_query_targetlist_def(query, query->targetList, context, rte); /* Add the FROM clause if needed */ get_from_clause(query, " FROM ", context); /* Add a WHERE clause if given */ if (query->jointree->quals != NULL) { appendContextKeyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_expr(query->jointree->quals, context, false); } /* Add RETURNING if present */ if (query->returningList) { appendContextKeyword(context, " RETURNING", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_target_list(query->returningList, context, NULL); } } /* ---------- * get_update_query_targetlist_def - Parse back an UPDATE targetlist * ---------- */ static void get_update_query_targetlist_def(Query *query, List *targetList, deparse_context *context, RangeTblEntry *rte) { StringInfo buf = context->buf; ListCell *l; ListCell *next_ma_cell; int remaining_ma_columns; const char *sep; SubLink *cur_ma_sublink; List *ma_sublinks; /* * Prepare to deal with MULTIEXPR assignments: collect the source SubLinks * into a list. We expect them to appear, in ID order, in resjunk tlist * entries. */ ma_sublinks = NIL; if (query->hasSubLinks) /* else there can't be any */ { foreach(l, targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resjunk && IsA(tle->expr, SubLink)) { SubLink *sl = (SubLink *) tle->expr; if (sl->subLinkType == MULTIEXPR_SUBLINK) { ma_sublinks = lappend(ma_sublinks, sl); Assert(sl->subLinkId == list_length(ma_sublinks)); } } } } next_ma_cell = list_head(ma_sublinks); cur_ma_sublink = NULL; remaining_ma_columns = 0; /* Add the comma separated list of 'attname = value' */ sep = ""; foreach(l, targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); Node *expr; if (tle->resjunk) continue; /* ignore junk entries */ /* Emit separator (OK whether we're in multiassignment or not) */ appendStringInfoString(buf, sep); sep = ", "; /* * Check to see if we're starting a multiassignment group: if so, * output a left paren. */ if (next_ma_cell != NULL && cur_ma_sublink == NULL) { /* * We must dig down into the expr to see if it's a PARAM_MULTIEXPR * Param. That could be buried under FieldStores and ArrayRefs * (cf processIndirection()), and underneath those there could be * an implicit type coercion. */ expr = (Node *) tle->expr; while (expr) { if (IsA(expr, FieldStore)) { FieldStore *fstore = (FieldStore *) expr; expr = (Node *) linitial(fstore->newvals); } else if (IsA(expr, ArrayRef)) { ArrayRef *aref = (ArrayRef *) expr; if (aref->refassgnexpr == NULL) break; expr = (Node *) aref->refassgnexpr; } else break; } expr = strip_implicit_coercions(expr); if (expr && IsA(expr, Param) && ((Param *) expr)->paramkind == PARAM_MULTIEXPR) { cur_ma_sublink = (SubLink *) lfirst(next_ma_cell); next_ma_cell = lnext(next_ma_cell); remaining_ma_columns = count_nonjunk_tlist_entries( ((Query *) cur_ma_sublink->subselect)->targetList); Assert(((Param *) expr)->paramid == ((cur_ma_sublink->subLinkId << 16) | 1)); appendStringInfoChar(buf, '('); } } /* * Put out name of target column; look in the catalogs, not at * tle->resname, since resname will fail to track RENAME. */ appendStringInfoString(buf, quote_identifier(get_relid_attribute_name(rte->relid, tle->resno))); /* * Print any indirection needed (subfields or subscripts), and strip * off the top-level nodes representing the indirection assignments. */ expr = processIndirection((Node *) tle->expr, context, true); /* * If we're in a multiassignment, skip printing anything more, unless * this is the last column; in which case, what we print should be the * sublink, not the Param. */ if (cur_ma_sublink != NULL) { if (--remaining_ma_columns > 0) continue; /* not the last column of multiassignment */ appendStringInfoChar(buf, ')'); expr = (Node *) cur_ma_sublink; cur_ma_sublink = NULL; } appendStringInfoString(buf, " = "); get_rule_expr(expr, context, false); } } /* ---------- * get_delete_query_def - Parse back a DELETE parsetree * ---------- */ static void get_delete_query_def(Query *query, deparse_context *context) { StringInfo buf = context->buf; RangeTblEntry *rte; /* Insert the WITH clause if given */ get_with_clause(query, context); /* * Start the query with DELETE FROM relname */ rte = rt_fetch(query->resultRelation, query->rtable); Assert(rte->rtekind == RTE_RELATION); if (PRETTY_INDENT(context)) { appendStringInfoChar(buf, ' '); context->indentLevel += PRETTYINDENT_STD; } appendStringInfo(buf, "DELETE FROM %s%s", only_marker(rte), generate_relation_name(rte->relid, NIL)); if (rte->alias != NULL) appendStringInfo(buf, " %s", quote_identifier(rte->alias->aliasname)); /* Add the USING clause if given */ get_from_clause(query, " USING ", context); /* Add a WHERE clause if given */ if (query->jointree->quals != NULL) { appendContextKeyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_rule_expr(query->jointree->quals, context, false); } /* Add RETURNING if present */ if (query->returningList) { appendContextKeyword(context, " RETURNING", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1); get_target_list(query->returningList, context, NULL); } } /* ---------- * get_utility_query_def - Parse back a UTILITY parsetree * ---------- */ static void get_utility_query_def(Query *query, deparse_context *context) { StringInfo buf = context->buf; if (query->utilityStmt && IsA(query->utilityStmt, NotifyStmt)) { NotifyStmt *stmt = (NotifyStmt *) query->utilityStmt; appendContextKeyword(context, "", 0, PRETTYINDENT_STD, 1); appendStringInfo(buf, "NOTIFY %s", quote_identifier(stmt->conditionname)); if (stmt->payload) { appendStringInfoString(buf, ", "); simple_quote_literal(buf, stmt->payload); } } else { /* Currently only NOTIFY utility commands can appear in rules */ elog(ERROR, "unexpected utility statement type"); } } /* * Display a Var appropriately. * * In some cases (currently only when recursing into an unnamed join) * the Var's varlevelsup has to be interpreted with respect to a context * above the current one; levelsup indicates the offset. * * If istoplevel is TRUE, the Var is at the top level of a SELECT's * targetlist, which means we need special treatment of whole-row Vars. * Instead of the normal "tab.*", we'll print "tab.*::typename", which is a * dirty hack to prevent "tab.*" from being expanded into multiple columns. * (The parser will strip the useless coercion, so no inefficiency is added in * dump and reload.) We used to print just "tab" in such cases, but that is * ambiguous and will yield the wrong result if "tab" is also a plain column * name in the query. * * Returns the attname of the Var, or NULL if the Var has no attname (because * it is a whole-row Var or a subplan output reference). */ static char * get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context) { StringInfo buf = context->buf; RangeTblEntry *rte; AttrNumber attnum; int netlevelsup; deparse_namespace *dpns; deparse_columns *colinfo; char *refname; char *attname; /* Find appropriate nesting depth */ netlevelsup = var->varlevelsup + levelsup; if (netlevelsup >= list_length(context->namespaces)) elog(ERROR, "bogus varlevelsup: %d offset %d", var->varlevelsup, levelsup); dpns = (deparse_namespace *) list_nth(context->namespaces, netlevelsup); /* * Try to find the relevant RTE in this rtable. In a plan tree, it's * likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig * down into the subplans, or INDEX_VAR, which is resolved similarly. Also * find the aliases previously assigned for this RTE. */ if (var->varno >= 1 && var->varno <= list_length(dpns->rtable)) { rte = rt_fetch(var->varno, dpns->rtable); refname = (char *) list_nth(dpns->rtable_names, var->varno - 1); colinfo = deparse_columns_fetch(var->varno, dpns); attnum = var->varattno; } else if (var->varno == OUTER_VAR && dpns->outer_tlist) { TargetEntry *tle; deparse_namespace save_dpns; tle = get_tle_by_resno(dpns->outer_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->outer_planstate, &save_dpns); /* * Force parentheses because our caller probably assumed a Var is a * simple expression. */ if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, '('); get_rule_expr((Node *) tle->expr, context, true); if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, ')'); pop_child_plan(dpns, &save_dpns); return NULL; } else if (var->varno == INNER_VAR && dpns->inner_tlist) { TargetEntry *tle; deparse_namespace save_dpns; tle = get_tle_by_resno(dpns->inner_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->inner_planstate, &save_dpns); /* * Force parentheses because our caller probably assumed a Var is a * simple expression. */ if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, '('); get_rule_expr((Node *) tle->expr, context, true); if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, ')'); pop_child_plan(dpns, &save_dpns); return NULL; } else if (var->varno == INDEX_VAR && dpns->index_tlist) { TargetEntry *tle; tle = get_tle_by_resno(dpns->index_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno); Assert(netlevelsup == 0); /* * Force parentheses because our caller probably assumed a Var is a * simple expression. */ if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, '('); get_rule_expr((Node *) tle->expr, context, true); if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, ')'); return NULL; } else { elog(ERROR, "bogus varno: %d", var->varno); return NULL; /* keep compiler quiet */ } /* * The planner will sometimes emit Vars referencing resjunk elements of a * subquery's target list (this is currently only possible if it chooses * to generate a "physical tlist" for a SubqueryScan or CteScan node). * Although we prefer to print subquery-referencing Vars using the * subquery's alias, that's not possible for resjunk items since they have * no alias. So in that case, drill down to the subplan and print the * contents of the referenced tlist item. This works because in a plan * tree, such Vars can only occur in a SubqueryScan or CteScan node, and * we'll have set dpns->inner_planstate to reference the child plan node. */ if ((rte->rtekind == RTE_SUBQUERY || rte->rtekind == RTE_CTE) && attnum > list_length(rte->eref->colnames) && dpns->inner_planstate) { TargetEntry *tle; deparse_namespace save_dpns; tle = get_tle_by_resno(dpns->inner_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for subquery var: %d", var->varattno); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->inner_planstate, &save_dpns); /* * Force parentheses because our caller probably assumed a Var is a * simple expression. */ if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, '('); get_rule_expr((Node *) tle->expr, context, true); if (!IsA(tle->expr, Var)) appendStringInfoChar(buf, ')'); pop_child_plan(dpns, &save_dpns); return NULL; } /* * If it's an unnamed join, look at the expansion of the alias variable. * If it's a simple reference to one of the input vars, then recursively * print the name of that var instead. When it's not a simple reference, * we have to just print the unqualified join column name. (This can only * happen with "dangerous" merged columns in a JOIN USING; we took pains * previously to make the unqualified column name unique in such cases.) * * This wouldn't work in decompiling plan trees, because we don't store * joinaliasvars lists after planning; but a plan tree should never * contain a join alias variable. */ if (rte->rtekind == RTE_JOIN && rte->alias == NULL) { if (rte->joinaliasvars == NIL) elog(ERROR, "cannot decompile join alias var in plan tree"); if (attnum > 0) { Var *aliasvar; aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1); /* we intentionally don't strip implicit coercions here */ if (aliasvar && IsA(aliasvar, Var)) { return get_variable(aliasvar, var->varlevelsup + levelsup, istoplevel, context); } } /* * Unnamed join has no refname. (Note: since it's unnamed, there is * no way the user could have referenced it to create a whole-row Var * for it. So we don't have to cover that case below.) */ Assert(refname == NULL); } if (attnum == InvalidAttrNumber) attname = NULL; else if (attnum > 0) { /* Get column name to use from the colinfo struct */ Assert(attnum <= colinfo->num_cols); attname = colinfo->colnames[attnum - 1]; Assert(attname != NULL); } else { /* System column - name is fixed, get it from the catalog */ attname = get_rte_attribute_name(rte, attnum); } if (refname && (context->varprefix || attname == NULL)) { appendStringInfoString(buf, quote_identifier(refname)); appendStringInfoChar(buf, '.'); } if (attname) appendStringInfoString(buf, quote_identifier(attname)); else { appendStringInfoChar(buf, '*'); if (istoplevel) appendStringInfo(buf, "::%s", format_type_with_typemod(var->vartype, var->vartypmod)); } return attname; } /* * Get the name of a field of an expression of composite type. The * expression is usually a Var, but we handle other cases too. * * levelsup is an extra offset to interpret the Var's varlevelsup correctly. * * This is fairly straightforward when the expression has a named composite * type; we need only look up the type in the catalogs. However, the type * could also be RECORD. Since no actual table or view column is allowed to * have type RECORD, a Var of type RECORD must refer to a JOIN or FUNCTION RTE * or to a subquery output. We drill down to find the ultimate defining * expression and attempt to infer the field name from it. We ereport if we * can't determine the name. * * Similarly, a PARAM of type RECORD has to refer to some expression of * a determinable composite type. */ static const char * get_name_for_var_field(Var *var, int fieldno, int levelsup, deparse_context *context) { RangeTblEntry *rte; AttrNumber attnum; int netlevelsup; deparse_namespace *dpns; TupleDesc tupleDesc; Node *expr; /* * If it's a RowExpr that was expanded from a whole-row Var, use the * column names attached to it. */ if (IsA(var, RowExpr)) { RowExpr *r = (RowExpr *) var; if (fieldno > 0 && fieldno <= list_length(r->colnames)) return strVal(list_nth(r->colnames, fieldno - 1)); } /* * If it's a Param of type RECORD, try to find what the Param refers to. */ if (IsA(var, Param)) { Param *param = (Param *) var; ListCell *ancestor_cell; expr = find_param_referent(param, context, &dpns, &ancestor_cell); if (expr) { /* Found a match, so recurse to decipher the field name */ deparse_namespace save_dpns; const char *result; push_ancestor_plan(dpns, ancestor_cell, &save_dpns); result = get_name_for_var_field((Var *) expr, fieldno, 0, context); pop_ancestor_plan(dpns, &save_dpns); return result; } } /* * If it's a Var of type RECORD, we have to find what the Var refers to; * if not, we can use get_expr_result_type. If that fails, we try * lookup_rowtype_tupdesc, which will probably fail too, but will ereport * an acceptable message. */ if (!IsA(var, Var) || var->vartype != RECORDOID) { if (get_expr_result_type((Node *) var, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE) tupleDesc = lookup_rowtype_tupdesc_copy(exprType((Node *) var), exprTypmod((Node *) var)); Assert(tupleDesc); /* Got the tupdesc, so we can extract the field name */ Assert(fieldno >= 1 && fieldno <= tupleDesc->natts); return NameStr(tupleDesc->attrs[fieldno - 1]->attname); } /* Find appropriate nesting depth */ netlevelsup = var->varlevelsup + levelsup; if (netlevelsup >= list_length(context->namespaces)) elog(ERROR, "bogus varlevelsup: %d offset %d", var->varlevelsup, levelsup); dpns = (deparse_namespace *) list_nth(context->namespaces, netlevelsup); /* * Try to find the relevant RTE in this rtable. In a plan tree, it's * likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig * down into the subplans, or INDEX_VAR, which is resolved similarly. */ if (var->varno >= 1 && var->varno <= list_length(dpns->rtable)) { rte = rt_fetch(var->varno, dpns->rtable); attnum = var->varattno; } else if (var->varno == OUTER_VAR && dpns->outer_tlist) { TargetEntry *tle; deparse_namespace save_dpns; const char *result; tle = get_tle_by_resno(dpns->outer_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->outer_planstate, &save_dpns); result = get_name_for_var_field((Var *) tle->expr, fieldno, levelsup, context); pop_child_plan(dpns, &save_dpns); return result; } else if (var->varno == INNER_VAR && dpns->inner_tlist) { TargetEntry *tle; deparse_namespace save_dpns; const char *result; tle = get_tle_by_resno(dpns->inner_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->inner_planstate, &save_dpns); result = get_name_for_var_field((Var *) tle->expr, fieldno, levelsup, context); pop_child_plan(dpns, &save_dpns); return result; } else if (var->varno == INDEX_VAR && dpns->index_tlist) { TargetEntry *tle; const char *result; tle = get_tle_by_resno(dpns->index_tlist, var->varattno); if (!tle) elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno); Assert(netlevelsup == 0); result = get_name_for_var_field((Var *) tle->expr, fieldno, levelsup, context); return result; } else { elog(ERROR, "bogus varno: %d", var->varno); return NULL; /* keep compiler quiet */ } if (attnum == InvalidAttrNumber) { /* Var is whole-row reference to RTE, so select the right field */ return get_rte_attribute_name(rte, fieldno); } /* * This part has essentially the same logic as the parser's * expandRecordVariable() function, but we are dealing with a different * representation of the input context, and we only need one field name * not a TupleDesc. Also, we need special cases for finding subquery and * CTE subplans when deparsing Plan trees. */ expr = (Node *) var; /* default if we can't drill down */ switch (rte->rtekind) { case RTE_RELATION: case RTE_VALUES: /* * This case should not occur: a column of a table or values list * shouldn't have type RECORD. Fall through and fail (most * likely) at the bottom. */ break; case RTE_SUBQUERY: /* Subselect-in-FROM: examine sub-select's output expr */ { if (rte->subquery) { TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList, attnum); if (ste == NULL || ste->resjunk) elog(ERROR, "subquery %s does not have attribute %d", rte->eref->aliasname, attnum); expr = (Node *) ste->expr; if (IsA(expr, Var)) { /* * Recurse into the sub-select to see what its Var * refers to. We have to build an additional level of * namespace to keep in step with varlevelsup in the * subselect. */ deparse_namespace mydpns; const char *result; set_deparse_for_query(&mydpns, rte->subquery, context->namespaces); context->namespaces = lcons(&mydpns, context->namespaces); result = get_name_for_var_field((Var *) expr, fieldno, 0, context); context->namespaces = list_delete_first(context->namespaces); return result; } /* else fall through to inspect the expression */ } else { /* * We're deparsing a Plan tree so we don't have complete * RTE entries (in particular, rte->subquery is NULL). But * the only place we'd see a Var directly referencing a * SUBQUERY RTE is in a SubqueryScan plan node, and we can * look into the child plan's tlist instead. */ TargetEntry *tle; deparse_namespace save_dpns; const char *result; if (!dpns->inner_planstate) elog(ERROR, "failed to find plan for subquery %s", rte->eref->aliasname); tle = get_tle_by_resno(dpns->inner_tlist, attnum); if (!tle) elog(ERROR, "bogus varattno for subquery var: %d", attnum); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->inner_planstate, &save_dpns); result = get_name_for_var_field((Var *) tle->expr, fieldno, levelsup, context); pop_child_plan(dpns, &save_dpns); return result; } } break; case RTE_JOIN: /* Join RTE --- recursively inspect the alias variable */ if (rte->joinaliasvars == NIL) elog(ERROR, "cannot decompile join alias var in plan tree"); Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars)); expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1); Assert(expr != NULL); /* we intentionally don't strip implicit coercions here */ if (IsA(expr, Var)) return get_name_for_var_field((Var *) expr, fieldno, var->varlevelsup + levelsup, context); /* else fall through to inspect the expression */ break; case RTE_FUNCTION: /* * We couldn't get here unless a function is declared with one of * its result columns as RECORD, which is not allowed. */ break; case RTE_CTE: /* CTE reference: examine subquery's output expr */ { CommonTableExpr *cte = NULL; Index ctelevelsup; ListCell *lc; /* * Try to find the referenced CTE using the namespace stack. */ ctelevelsup = rte->ctelevelsup + netlevelsup; if (ctelevelsup >= list_length(context->namespaces)) lc = NULL; else { deparse_namespace *ctedpns; ctedpns = (deparse_namespace *) list_nth(context->namespaces, ctelevelsup); foreach(lc, ctedpns->ctes) { cte = (CommonTableExpr *) lfirst(lc); if (strcmp(cte->ctename, rte->ctename) == 0) break; } } if (lc != NULL) { Query *ctequery = (Query *) cte->ctequery; TargetEntry *ste = get_tle_by_resno(GetCTETargetList(cte), attnum); if (ste == NULL || ste->resjunk) elog(ERROR, "subquery %s does not have attribute %d", rte->eref->aliasname, attnum); expr = (Node *) ste->expr; if (IsA(expr, Var)) { /* * Recurse into the CTE to see what its Var refers to. * We have to build an additional level of namespace * to keep in step with varlevelsup in the CTE. * Furthermore it could be an outer CTE, so we may * have to delete some levels of namespace. */ List *save_nslist = context->namespaces; List *new_nslist; deparse_namespace mydpns; const char *result; set_deparse_for_query(&mydpns, ctequery, context->namespaces); new_nslist = list_copy_tail(context->namespaces, ctelevelsup); context->namespaces = lcons(&mydpns, new_nslist); result = get_name_for_var_field((Var *) expr, fieldno, 0, context); context->namespaces = save_nslist; return result; } /* else fall through to inspect the expression */ } else { /* * We're deparsing a Plan tree so we don't have a CTE * list. But the only place we'd see a Var directly * referencing a CTE RTE is in a CteScan plan node, and we * can look into the subplan's tlist instead. */ TargetEntry *tle; deparse_namespace save_dpns; const char *result; if (!dpns->inner_planstate) elog(ERROR, "failed to find plan for CTE %s", rte->eref->aliasname); tle = get_tle_by_resno(dpns->inner_tlist, attnum); if (!tle) elog(ERROR, "bogus varattno for subquery var: %d", attnum); Assert(netlevelsup == 0); push_child_plan(dpns, dpns->inner_planstate, &save_dpns); result = get_name_for_var_field((Var *) tle->expr, fieldno, levelsup, context); pop_child_plan(dpns, &save_dpns); return result; } } break; } /* * We now have an expression we can't expand any more, so see if * get_expr_result_type() can do anything with it. If not, pass to * lookup_rowtype_tupdesc() which will probably fail, but will give an * appropriate error message while failing. */ if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE) tupleDesc = lookup_rowtype_tupdesc_copy(exprType(expr), exprTypmod(expr)); Assert(tupleDesc); /* Got the tupdesc, so we can extract the field name */ Assert(fieldno >= 1 && fieldno <= tupleDesc->natts); return NameStr(tupleDesc->attrs[fieldno - 1]->attname); } /* * Try to find the referenced expression for a PARAM_EXEC Param that might * reference a parameter supplied by an upper NestLoop or SubPlan plan node. * * If successful, return the expression and set *dpns_p and *ancestor_cell_p * appropriately for calling push_ancestor_plan(). If no referent can be * found, return NULL. */ static Node * find_param_referent(Param *param, deparse_context *context, deparse_namespace **dpns_p, ListCell **ancestor_cell_p) { /* Initialize output parameters to prevent compiler warnings */ *dpns_p = NULL; *ancestor_cell_p = NULL; /* * If it's a PARAM_EXEC parameter, look for a matching NestLoopParam or * SubPlan argument. This will necessarily be in some ancestor of the * current expression's PlanState. */ if (param->paramkind == PARAM_EXEC) { deparse_namespace *dpns; PlanState *child_ps; bool in_same_plan_level; ListCell *lc; dpns = (deparse_namespace *) linitial(context->namespaces); child_ps = dpns->planstate; in_same_plan_level = true; foreach(lc, dpns->ancestors) { PlanState *ps = (PlanState *) lfirst(lc); ListCell *lc2; /* * NestLoops transmit params to their inner child only; also, once * we've crawled up out of a subplan, this couldn't possibly be * the right match. */ if (IsA(ps, NestLoopState) && child_ps == innerPlanState(ps) && in_same_plan_level) { NestLoop *nl = (NestLoop *) ps->plan; foreach(lc2, nl->nestParams) { NestLoopParam *nlp = (NestLoopParam *) lfirst(lc2); if (nlp->paramno == param->paramid) { /* Found a match, so return it */ *dpns_p = dpns; *ancestor_cell_p = lc; return (Node *) nlp->paramval; } } } /* * Check to see if we're crawling up from a subplan. */ foreach(lc2, ps->subPlan) { SubPlanState *sstate = (SubPlanState *) lfirst(lc2); SubPlan *subplan = (SubPlan *) sstate->xprstate.expr; ListCell *lc3; ListCell *lc4; if (child_ps != sstate->planstate) continue; /* Matched subplan, so check its arguments */ forboth(lc3, subplan->parParam, lc4, subplan->args) { int paramid = lfirst_int(lc3); Node *arg = (Node *) lfirst(lc4); if (paramid == param->paramid) { /* Found a match, so return it */ *dpns_p = dpns; *ancestor_cell_p = lc; return arg; } } /* Keep looking, but we are emerging from a subplan. */ in_same_plan_level = false; break; } /* * Likewise check to see if we're emerging from an initplan. * Initplans never have any parParams, so no need to search that * list, but we need to know if we should reset * in_same_plan_level. */ foreach(lc2, ps->initPlan) { SubPlanState *sstate = (SubPlanState *) lfirst(lc2); if (child_ps != sstate->planstate) continue; /* No parameters to be had here. */ Assert(((SubPlan *) sstate->xprstate.expr)->parParam == NIL); /* Keep looking, but we are emerging from an initplan. */ in_same_plan_level = false; break; } /* No luck, crawl up to next ancestor */ child_ps = ps; } } /* No referent found */ return NULL; } /* * Display a Param appropriately. */ static void get_parameter(Param *param, deparse_context *context) { Node *expr; deparse_namespace *dpns; ListCell *ancestor_cell; /* * If it's a PARAM_EXEC parameter, try to locate the expression from which * the parameter was computed. Note that failing to find a referent isn't * an error, since the Param might well be a subplan output rather than an * input. */ expr = find_param_referent(param, context, &dpns, &ancestor_cell); if (expr) { /* Found a match, so print it */ deparse_namespace save_dpns; bool save_varprefix; bool need_paren; /* Switch attention to the ancestor plan node */ push_ancestor_plan(dpns, ancestor_cell, &save_dpns); /* * Force prefixing of Vars, since they won't belong to the relation * being scanned in the original plan node. */ save_varprefix = context->varprefix; context->varprefix = true; /* * A Param's expansion is typically a Var, Aggref, or upper-level * Param, which wouldn't need extra parentheses. Otherwise, insert * parens to ensure the expression looks atomic. */ need_paren = !(IsA(expr, Var) || IsA(expr, Aggref) || IsA(expr, Param)); if (need_paren) appendStringInfoChar(context->buf, '('); get_rule_expr(expr, context, false); if (need_paren) appendStringInfoChar(context->buf, ')'); context->varprefix = save_varprefix; pop_ancestor_plan(dpns, &save_dpns); return; } /* * Not PARAM_EXEC, or couldn't find referent: just print $N. */ appendStringInfo(context->buf, "$%d", param->paramid); } /* * get_simple_binary_op_name * * helper function for isSimpleNode * will return single char binary operator name, or NULL if it's not */ static const char * get_simple_binary_op_name(OpExpr *expr) { List *args = expr->args; if (list_length(args) == 2) { /* binary operator */ Node *arg1 = (Node *) linitial(args); Node *arg2 = (Node *) lsecond(args); const char *op; op = generate_operator_name(expr->opno, exprType(arg1), exprType(arg2)); if (strlen(op) == 1) return op; } return NULL; } /* * isSimpleNode - check if given node is simple (doesn't need parenthesizing) * * true : simple in the context of parent node's type * false : not simple */ static bool isSimpleNode(Node *node, Node *parentNode, int prettyFlags) { if (!node) return false; switch (nodeTag(node)) { case T_Var: case T_Const: case T_Param: case T_CoerceToDomainValue: case T_SetToDefault: case T_CurrentOfExpr: /* single words: always simple */ return true; case T_ArrayRef: case T_ArrayExpr: case T_RowExpr: case T_CoalesceExpr: case T_MinMaxExpr: case T_XmlExpr: case T_NullIfExpr: case T_Aggref: case T_WindowFunc: case T_FuncExpr: /* function-like: name(..) or name[..] */ return true; /* CASE keywords act as parentheses */ case T_CaseExpr: return true; case T_FieldSelect: /* * appears simple since . has top precedence, unless parent is * T_FieldSelect itself! */ return (IsA(parentNode, FieldSelect) ? false : true); case T_FieldStore: /* * treat like FieldSelect (probably doesn't matter) */ return (IsA(parentNode, FieldStore) ? false : true); case T_CoerceToDomain: /* maybe simple, check args */ return isSimpleNode((Node *) ((CoerceToDomain *) node)->arg, node, prettyFlags); case T_RelabelType: return isSimpleNode((Node *) ((RelabelType *) node)->arg, node, prettyFlags); case T_CoerceViaIO: return isSimpleNode((Node *) ((CoerceViaIO *) node)->arg, node, prettyFlags); case T_ArrayCoerceExpr: return isSimpleNode((Node *) ((ArrayCoerceExpr *) node)->arg, node, prettyFlags); case T_ConvertRowtypeExpr: return isSimpleNode((Node *) ((ConvertRowtypeExpr *) node)->arg, node, prettyFlags); case T_OpExpr: { /* depends on parent node type; needs further checking */ if (prettyFlags & PRETTYFLAG_PAREN && IsA(parentNode, OpExpr)) { const char *op; const char *parentOp; bool is_lopriop; bool is_hipriop; bool is_lopriparent; bool is_hipriparent; op = get_simple_binary_op_name((OpExpr *) node); if (!op) return false; /* We know only the basic operators + - and * / % */ is_lopriop = (strchr("+-", *op) != NULL); is_hipriop = (strchr("*/%", *op) != NULL); if (!(is_lopriop || is_hipriop)) return false; parentOp = get_simple_binary_op_name((OpExpr *) parentNode); if (!parentOp) return false; is_lopriparent = (strchr("+-", *parentOp) != NULL); is_hipriparent = (strchr("*/%", *parentOp) != NULL); if (!(is_lopriparent || is_hipriparent)) return false; if (is_hipriop && is_lopriparent) return true; /* op binds tighter than parent */ if (is_lopriop && is_hipriparent) return false; /* * Operators are same priority --- can skip parens only if * we have (a - b) - c, not a - (b - c). */ if (node == (Node *) linitial(((OpExpr *) parentNode)->args)) return true; return false; } /* else do the same stuff as for T_SubLink et al. */ /* FALL THROUGH */ } case T_SubLink: case T_NullTest: case T_BooleanTest: case T_DistinctExpr: switch (nodeTag(parentNode)) { case T_FuncExpr: { /* special handling for casts */ CoercionForm type = ((FuncExpr *) parentNode)->funcformat; if (type == COERCE_EXPLICIT_CAST || type == COERCE_IMPLICIT_CAST) return false; return true; /* own parentheses */ } case T_BoolExpr: /* lower precedence */ case T_ArrayRef: /* other separators */ case T_ArrayExpr: /* other separators */ case T_RowExpr: /* other separators */ case T_CoalesceExpr: /* own parentheses */ case T_MinMaxExpr: /* own parentheses */ case T_XmlExpr: /* own parentheses */ case T_NullIfExpr: /* other separators */ case T_Aggref: /* own parentheses */ case T_WindowFunc: /* own parentheses */ case T_CaseExpr: /* other separators */ return true; default: return false; } case T_BoolExpr: switch (nodeTag(parentNode)) { case T_BoolExpr: if (prettyFlags & PRETTYFLAG_PAREN) { BoolExprType type; BoolExprType parentType; type = ((BoolExpr *) node)->boolop; parentType = ((BoolExpr *) parentNode)->boolop; switch (type) { case NOT_EXPR: case AND_EXPR: if (parentType == AND_EXPR || parentType == OR_EXPR) return true; break; case OR_EXPR: if (parentType == OR_EXPR) return true; break; } } return false; case T_FuncExpr: { /* special handling for casts */ CoercionForm type = ((FuncExpr *) parentNode)->funcformat; if (type == COERCE_EXPLICIT_CAST || type == COERCE_IMPLICIT_CAST) return false; return true; /* own parentheses */ } case T_ArrayRef: /* other separators */ case T_ArrayExpr: /* other separators */ case T_RowExpr: /* other separators */ case T_CoalesceExpr: /* own parentheses */ case T_MinMaxExpr: /* own parentheses */ case T_XmlExpr: /* own parentheses */ case T_NullIfExpr: /* other separators */ case T_Aggref: /* own parentheses */ case T_WindowFunc: /* own parentheses */ case T_CaseExpr: /* other separators */ return true; default: return false; } default: break; } /* those we don't know: in dubio complexo */ return false; } /* * appendContextKeyword - append a keyword to buffer * * If prettyPrint is enabled, perform a line break, and adjust indentation. * Otherwise, just append the keyword. */ static void appendContextKeyword(deparse_context *context, const char *str, int indentBefore, int indentAfter, int indentPlus) { StringInfo buf = context->buf; if (PRETTY_INDENT(context)) { int indentAmount; context->indentLevel += indentBefore; /* remove any trailing spaces currently in the buffer ... */ removeStringInfoSpaces(buf); /* ... then add a newline and some spaces */ appendStringInfoChar(buf, '\n'); if (context->indentLevel < PRETTYINDENT_LIMIT) indentAmount = Max(context->indentLevel, 0) + indentPlus; else { /* * If we're indented more than PRETTYINDENT_LIMIT characters, try * to conserve horizontal space by reducing the per-level * indentation. For best results the scale factor here should * divide all the indent amounts that get added to indentLevel * (PRETTYINDENT_STD, etc). It's important that the indentation * not grow unboundedly, else deeply-nested trees use O(N^2) * whitespace; so we also wrap modulo PRETTYINDENT_LIMIT. */ indentAmount = PRETTYINDENT_LIMIT + (context->indentLevel - PRETTYINDENT_LIMIT) / (PRETTYINDENT_STD / 2); indentAmount %= PRETTYINDENT_LIMIT; /* scale/wrap logic affects indentLevel, but not indentPlus */ indentAmount += indentPlus; } appendStringInfoSpaces(buf, indentAmount); appendStringInfoString(buf, str); context->indentLevel += indentAfter; if (context->indentLevel < 0) context->indentLevel = 0; } else appendStringInfoString(buf, str); } /* * removeStringInfoSpaces - delete trailing spaces from a buffer. * * Possibly this should move to stringinfo.c at some point. */ static void removeStringInfoSpaces(StringInfo str) { while (str->len > 0 && str->data[str->len - 1] == ' ') str->data[--(str->len)] = '\0'; } /* * get_rule_expr_paren - deparse expr using get_rule_expr, * embracing the string with parentheses if necessary for prettyPrint. * * Never embrace if prettyFlags=0, because it's done in the calling node. * * Any node that does *not* embrace its argument node by sql syntax (with * parentheses, non-operator keywords like CASE/WHEN/ON, or comma etc) should * use get_rule_expr_paren instead of get_rule_expr so parentheses can be * added. */ static void get_rule_expr_paren(Node *node, deparse_context *context, bool showimplicit, Node *parentNode) { bool need_paren; need_paren = PRETTY_PAREN(context) && !isSimpleNode(node, parentNode, context->prettyFlags); if (need_paren) appendStringInfoChar(context->buf, '('); get_rule_expr(node, context, showimplicit); if (need_paren) appendStringInfoChar(context->buf, ')'); } /* ---------- * get_rule_expr - Parse back an expression * * Note: showimplicit determines whether we display any implicit cast that * is present at the top of the expression tree. It is a passed argument, * not a field of the context struct, because we change the value as we * recurse down into the expression. In general we suppress implicit casts * when the result type is known with certainty (eg, the arguments of an * OR must be boolean). We display implicit casts for arguments of functions * and operators, since this is needed to be certain that the same function * or operator will be chosen when the expression is re-parsed. * ---------- */ static void get_rule_expr(Node *node, deparse_context *context, bool showimplicit) { StringInfo buf = context->buf; if (node == NULL) return; /* Guard against excessively long or deeply-nested queries */ CHECK_FOR_INTERRUPTS(); check_stack_depth(); /* * Each level of get_rule_expr must emit an indivisible term * (parenthesized if necessary) to ensure result is reparsed into the same * expression tree. The only exception is that when the input is a List, * we emit the component items comma-separated with no surrounding * decoration; this is convenient for most callers. */ switch (nodeTag(node)) { case T_Var: (void) get_variable((Var *) node, 0, false, context); break; case T_Const: get_const_expr((Const *) node, context, 0); break; case T_Param: get_parameter((Param *) node, context); break; case T_Aggref: get_agg_expr((Aggref *) node, context); break; case T_GroupingFunc: { GroupingFunc *gexpr = (GroupingFunc *) node; appendStringInfoString(buf, "GROUPING("); get_rule_expr((Node *) gexpr->args, context, true); appendStringInfoChar(buf, ')'); } break; case T_WindowFunc: get_windowfunc_expr((WindowFunc *) node, context); break; case T_ArrayRef: { ArrayRef *aref = (ArrayRef *) node; bool need_parens; /* * If the argument is a CaseTestExpr, we must be inside a * FieldStore, ie, we are assigning to an element of an array * within a composite column. Since we already punted on * displaying the FieldStore's target information, just punt * here too, and display only the assignment source * expression. */ if (IsA(aref->refexpr, CaseTestExpr)) { Assert(aref->refassgnexpr); get_rule_expr((Node *) aref->refassgnexpr, context, showimplicit); break; } /* * Parenthesize the argument unless it's a simple Var or a * FieldSelect. (In particular, if it's another ArrayRef, we * *must* parenthesize to avoid confusion.) */ need_parens = !IsA(aref->refexpr, Var) && !IsA(aref->refexpr, FieldSelect); if (need_parens) appendStringInfoChar(buf, '('); get_rule_expr((Node *) aref->refexpr, context, showimplicit); if (need_parens) appendStringInfoChar(buf, ')'); /* * If there's a refassgnexpr, we want to print the node in the * format "array[subscripts] := refassgnexpr". This is not * legal SQL, so decompilation of INSERT or UPDATE statements * should always use processIndirection as part of the * statement-level syntax. We should only see this when * EXPLAIN tries to print the targetlist of a plan resulting * from such a statement. */ if (aref->refassgnexpr) { Node *refassgnexpr; /* * Use processIndirection to print this node's subscripts * as well as any additional field selections or * subscripting in immediate descendants. It returns the * RHS expr that is actually being "assigned". */ refassgnexpr = processIndirection(node, context, true); appendStringInfoString(buf, " := "); get_rule_expr(refassgnexpr, context, showimplicit); } else { /* Just an ordinary array fetch, so print subscripts */ printSubscripts(aref, context); } } break; case T_FuncExpr: get_func_expr((FuncExpr *) node, context, showimplicit); break; case T_NamedArgExpr: { NamedArgExpr *na = (NamedArgExpr *) node; appendStringInfo(buf, "%s => ", quote_identifier(na->name)); get_rule_expr((Node *) na->arg, context, showimplicit); } break; case T_OpExpr: get_oper_expr((OpExpr *) node, context); break; case T_DistinctExpr: { DistinctExpr *expr = (DistinctExpr *) node; List *args = expr->args; Node *arg1 = (Node *) linitial(args); Node *arg2 = (Node *) lsecond(args); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(arg1, context, true, node); appendStringInfoString(buf, " IS DISTINCT FROM "); get_rule_expr_paren(arg2, context, true, node); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } break; case T_NullIfExpr: { NullIfExpr *nullifexpr = (NullIfExpr *) node; appendStringInfoString(buf, "NULLIF("); get_rule_expr((Node *) nullifexpr->args, context, true); appendStringInfoChar(buf, ')'); } break; case T_ScalarArrayOpExpr: { ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node; List *args = expr->args; Node *arg1 = (Node *) linitial(args); Node *arg2 = (Node *) lsecond(args); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(arg1, context, true, node); appendStringInfo(buf, " %s %s (", generate_operator_name(expr->opno, exprType(arg1), get_base_element_type(exprType(arg2))), expr->useOr ? "ANY" : "ALL"); get_rule_expr_paren(arg2, context, true, node); appendStringInfoChar(buf, ')'); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } break; case T_BoolExpr: { BoolExpr *expr = (BoolExpr *) node; Node *first_arg = linitial(expr->args); ListCell *arg = lnext(list_head(expr->args)); switch (expr->boolop) { case AND_EXPR: if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(first_arg, context, false, node); while (arg) { appendStringInfoString(buf, " AND "); get_rule_expr_paren((Node *) lfirst(arg), context, false, node); arg = lnext(arg); } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); break; case OR_EXPR: if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(first_arg, context, false, node); while (arg) { appendStringInfoString(buf, " OR "); get_rule_expr_paren((Node *) lfirst(arg), context, false, node); arg = lnext(arg); } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); break; case NOT_EXPR: if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); appendStringInfoString(buf, "NOT "); get_rule_expr_paren(first_arg, context, false, node); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); break; default: elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop); } } break; case T_SubLink: get_sublink_expr((SubLink *) node, context); break; case T_SubPlan: { SubPlan *subplan = (SubPlan *) node; /* * We cannot see an already-planned subplan in rule deparsing, * only while EXPLAINing a query plan. We don't try to * reconstruct the original SQL, just reference the subplan * that appears elsewhere in EXPLAIN's result. */ if (subplan->useHashTable) appendStringInfo(buf, "(hashed %s)", subplan->plan_name); else appendStringInfo(buf, "(%s)", subplan->plan_name); } break; case T_AlternativeSubPlan: { AlternativeSubPlan *asplan = (AlternativeSubPlan *) node; ListCell *lc; /* As above, this can only happen during EXPLAIN */ appendStringInfoString(buf, "(alternatives: "); foreach(lc, asplan->subplans) { SubPlan *splan = (SubPlan *) lfirst(lc); Assert(IsA(splan, SubPlan)); if (splan->useHashTable) appendStringInfo(buf, "hashed %s", splan->plan_name); else appendStringInfoString(buf, splan->plan_name); if (lnext(lc)) appendStringInfoString(buf, " or "); } appendStringInfoChar(buf, ')'); } break; case T_FieldSelect: { FieldSelect *fselect = (FieldSelect *) node; Node *arg = (Node *) fselect->arg; int fno = fselect->fieldnum; const char *fieldname; bool need_parens; /* * Parenthesize the argument unless it's an ArrayRef or * another FieldSelect. Note in particular that it would be * WRONG to not parenthesize a Var argument; simplicity is not * the issue here, having the right number of names is. */ need_parens = !IsA(arg, ArrayRef) &&!IsA(arg, FieldSelect); if (need_parens) appendStringInfoChar(buf, '('); get_rule_expr(arg, context, true); if (need_parens) appendStringInfoChar(buf, ')'); /* * Get and print the field name. */ fieldname = get_name_for_var_field((Var *) arg, fno, 0, context); appendStringInfo(buf, ".%s", quote_identifier(fieldname)); } break; case T_FieldStore: { FieldStore *fstore = (FieldStore *) node; bool need_parens; /* * There is no good way to represent a FieldStore as real SQL, * so decompilation of INSERT or UPDATE statements should * always use processIndirection as part of the * statement-level syntax. We should only get here when * EXPLAIN tries to print the targetlist of a plan resulting * from such a statement. The plan case is even harder than * ordinary rules would be, because the planner tries to * collapse multiple assignments to the same field or subfield * into one FieldStore; so we can see a list of target fields * not just one, and the arguments could be FieldStores * themselves. We don't bother to try to print the target * field names; we just print the source arguments, with a * ROW() around them if there's more than one. This isn't * terribly complete, but it's probably good enough for * EXPLAIN's purposes; especially since anything more would be * either hopelessly confusing or an even poorer * representation of what the plan is actually doing. */ need_parens = (list_length(fstore->newvals) != 1); if (need_parens) appendStringInfoString(buf, "ROW("); get_rule_expr((Node *) fstore->newvals, context, showimplicit); if (need_parens) appendStringInfoChar(buf, ')'); } break; case T_RelabelType: { RelabelType *relabel = (RelabelType *) node; Node *arg = (Node *) relabel->arg; if (relabel->relabelformat == COERCE_IMPLICIT_CAST && !showimplicit) { /* don't show the implicit cast */ get_rule_expr_paren(arg, context, false, node); } else { get_coercion_expr(arg, context, relabel->resulttype, relabel->resulttypmod, node); } } break; case T_CoerceViaIO: { CoerceViaIO *iocoerce = (CoerceViaIO *) node; Node *arg = (Node *) iocoerce->arg; if (iocoerce->coerceformat == COERCE_IMPLICIT_CAST && !showimplicit) { /* don't show the implicit cast */ get_rule_expr_paren(arg, context, false, node); } else { get_coercion_expr(arg, context, iocoerce->resulttype, -1, node); } } break; case T_ArrayCoerceExpr: { ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node; Node *arg = (Node *) acoerce->arg; if (acoerce->coerceformat == COERCE_IMPLICIT_CAST && !showimplicit) { /* don't show the implicit cast */ get_rule_expr_paren(arg, context, false, node); } else { get_coercion_expr(arg, context, acoerce->resulttype, acoerce->resulttypmod, node); } } break; case T_ConvertRowtypeExpr: { ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) node; Node *arg = (Node *) convert->arg; if (convert->convertformat == COERCE_IMPLICIT_CAST && !showimplicit) { /* don't show the implicit cast */ get_rule_expr_paren(arg, context, false, node); } else { get_coercion_expr(arg, context, convert->resulttype, -1, node); } } break; case T_CollateExpr: { CollateExpr *collate = (CollateExpr *) node; Node *arg = (Node *) collate->arg; if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(arg, context, showimplicit, node); appendStringInfo(buf, " COLLATE %s", generate_collation_name(collate->collOid)); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } break; case T_CaseExpr: { CaseExpr *caseexpr = (CaseExpr *) node; ListCell *temp; appendContextKeyword(context, "CASE", 0, PRETTYINDENT_VAR, 0); if (caseexpr->arg) { appendStringInfoChar(buf, ' '); get_rule_expr((Node *) caseexpr->arg, context, true); } foreach(temp, caseexpr->args) { CaseWhen *when = (CaseWhen *) lfirst(temp); Node *w = (Node *) when->expr; if (caseexpr->arg) { /* * The parser should have produced WHEN clauses of the * form "CaseTestExpr = RHS", possibly with an * implicit coercion inserted above the CaseTestExpr. * For accurate decompilation of rules it's essential * that we show just the RHS. However in an * expression that's been through the optimizer, the * WHEN clause could be almost anything (since the * equality operator could have been expanded into an * inline function). If we don't recognize the form * of the WHEN clause, just punt and display it as-is. */ if (IsA(w, OpExpr)) { List *args = ((OpExpr *) w)->args; if (list_length(args) == 2 && IsA(strip_implicit_coercions(linitial(args)), CaseTestExpr)) w = (Node *) lsecond(args); } } if (!PRETTY_INDENT(context)) appendStringInfoChar(buf, ' '); appendContextKeyword(context, "WHEN ", 0, 0, 0); get_rule_expr(w, context, false); appendStringInfoString(buf, " THEN "); get_rule_expr((Node *) when->result, context, true); } if (!PRETTY_INDENT(context)) appendStringInfoChar(buf, ' '); appendContextKeyword(context, "ELSE ", 0, 0, 0); get_rule_expr((Node *) caseexpr->defresult, context, true); if (!PRETTY_INDENT(context)) appendStringInfoChar(buf, ' '); appendContextKeyword(context, "END", -PRETTYINDENT_VAR, 0, 0); } break; case T_CaseTestExpr: { /* * Normally we should never get here, since for expressions * that can contain this node type we attempt to avoid * recursing to it. But in an optimized expression we might * be unable to avoid that (see comments for CaseExpr). If we * do see one, print it as CASE_TEST_EXPR. */ appendStringInfoString(buf, "CASE_TEST_EXPR"); } break; case T_ArrayExpr: { ArrayExpr *arrayexpr = (ArrayExpr *) node; appendStringInfoString(buf, "ARRAY["); get_rule_expr((Node *) arrayexpr->elements, context, true); appendStringInfoChar(buf, ']'); /* * If the array isn't empty, we assume its elements are * coerced to the desired type. If it's empty, though, we * need an explicit coercion to the array type. */ if (arrayexpr->elements == NIL) appendStringInfo(buf, "::%s", format_type_with_typemod(arrayexpr->array_typeid, -1)); } break; case T_RowExpr: { RowExpr *rowexpr = (RowExpr *) node; TupleDesc tupdesc = NULL; ListCell *arg; int i; char *sep; /* * If it's a named type and not RECORD, we may have to skip * dropped columns and/or claim there are NULLs for added * columns. */ if (rowexpr->row_typeid != RECORDOID) { tupdesc = lookup_rowtype_tupdesc(rowexpr->row_typeid, -1); Assert(list_length(rowexpr->args) <= tupdesc->natts); } /* * SQL99 allows "ROW" to be omitted when there is more than * one column, but for simplicity we always print it. */ appendStringInfoString(buf, "ROW("); sep = ""; i = 0; foreach(arg, rowexpr->args) { Node *e = (Node *) lfirst(arg); if (tupdesc == NULL || !tupdesc->attrs[i]->attisdropped) { appendStringInfoString(buf, sep); /* Whole-row Vars need special treatment here */ get_rule_expr_toplevel(e, context, true); sep = ", "; } i++; } if (tupdesc != NULL) { while (i < tupdesc->natts) { if (!tupdesc->attrs[i]->attisdropped) { appendStringInfoString(buf, sep); appendStringInfoString(buf, "NULL"); sep = ", "; } i++; } ReleaseTupleDesc(tupdesc); } appendStringInfoChar(buf, ')'); if (rowexpr->row_format == COERCE_EXPLICIT_CAST) appendStringInfo(buf, "::%s", format_type_with_typemod(rowexpr->row_typeid, -1)); } break; case T_RowCompareExpr: { RowCompareExpr *rcexpr = (RowCompareExpr *) node; ListCell *arg; char *sep; /* * SQL99 allows "ROW" to be omitted when there is more than * one column, but for simplicity we always print it. */ appendStringInfoString(buf, "(ROW("); sep = ""; foreach(arg, rcexpr->largs) { Node *e = (Node *) lfirst(arg); appendStringInfoString(buf, sep); get_rule_expr(e, context, true); sep = ", "; } /* * We assume that the name of the first-column operator will * do for all the rest too. This is definitely open to * failure, eg if some but not all operators were renamed * since the construct was parsed, but there seems no way to * be perfect. */ appendStringInfo(buf, ") %s ROW(", generate_operator_name(linitial_oid(rcexpr->opnos), exprType(linitial(rcexpr->largs)), exprType(linitial(rcexpr->rargs)))); sep = ""; foreach(arg, rcexpr->rargs) { Node *e = (Node *) lfirst(arg); appendStringInfoString(buf, sep); get_rule_expr(e, context, true); sep = ", "; } appendStringInfoString(buf, "))"); } break; case T_CoalesceExpr: { CoalesceExpr *coalesceexpr = (CoalesceExpr *) node; appendStringInfoString(buf, "COALESCE("); get_rule_expr((Node *) coalesceexpr->args, context, true); appendStringInfoChar(buf, ')'); } break; case T_MinMaxExpr: { MinMaxExpr *minmaxexpr = (MinMaxExpr *) node; switch (minmaxexpr->op) { case IS_GREATEST: appendStringInfoString(buf, "GREATEST("); break; case IS_LEAST: appendStringInfoString(buf, "LEAST("); break; } get_rule_expr((Node *) minmaxexpr->args, context, true); appendStringInfoChar(buf, ')'); } break; case T_XmlExpr: { XmlExpr *xexpr = (XmlExpr *) node; bool needcomma = false; ListCell *arg; ListCell *narg; Const *con; switch (xexpr->op) { case IS_XMLCONCAT: appendStringInfoString(buf, "XMLCONCAT("); break; case IS_XMLELEMENT: appendStringInfoString(buf, "XMLELEMENT("); break; case IS_XMLFOREST: appendStringInfoString(buf, "XMLFOREST("); break; case IS_XMLPARSE: appendStringInfoString(buf, "XMLPARSE("); break; case IS_XMLPI: appendStringInfoString(buf, "XMLPI("); break; case IS_XMLROOT: appendStringInfoString(buf, "XMLROOT("); break; case IS_XMLSERIALIZE: appendStringInfoString(buf, "XMLSERIALIZE("); break; case IS_DOCUMENT: break; } if (xexpr->op == IS_XMLPARSE || xexpr->op == IS_XMLSERIALIZE) { if (xexpr->xmloption == XMLOPTION_DOCUMENT) appendStringInfoString(buf, "DOCUMENT "); else appendStringInfoString(buf, "CONTENT "); } if (xexpr->name) { appendStringInfo(buf, "NAME %s", quote_identifier(map_xml_name_to_sql_identifier(xexpr->name))); needcomma = true; } if (xexpr->named_args) { if (xexpr->op != IS_XMLFOREST) { if (needcomma) appendStringInfoString(buf, ", "); appendStringInfoString(buf, "XMLATTRIBUTES("); needcomma = false; } forboth(arg, xexpr->named_args, narg, xexpr->arg_names) { Node *e = (Node *) lfirst(arg); char *argname = strVal(lfirst(narg)); if (needcomma) appendStringInfoString(buf, ", "); get_rule_expr((Node *) e, context, true); appendStringInfo(buf, " AS %s", quote_identifier(map_xml_name_to_sql_identifier(argname))); needcomma = true; } if (xexpr->op != IS_XMLFOREST) appendStringInfoChar(buf, ')'); } if (xexpr->args) { if (needcomma) appendStringInfoString(buf, ", "); switch (xexpr->op) { case IS_XMLCONCAT: case IS_XMLELEMENT: case IS_XMLFOREST: case IS_XMLPI: case IS_XMLSERIALIZE: /* no extra decoration needed */ get_rule_expr((Node *) xexpr->args, context, true); break; case IS_XMLPARSE: Assert(list_length(xexpr->args) == 2); get_rule_expr((Node *) linitial(xexpr->args), context, true); con = (Const *) lsecond(xexpr->args); Assert(IsA(con, Const)); Assert(!con->constisnull); if (DatumGetBool(con->constvalue)) appendStringInfoString(buf, " PRESERVE WHITESPACE"); else appendStringInfoString(buf, " STRIP WHITESPACE"); break; case IS_XMLROOT: Assert(list_length(xexpr->args) == 3); get_rule_expr((Node *) linitial(xexpr->args), context, true); appendStringInfoString(buf, ", VERSION "); con = (Const *) lsecond(xexpr->args); if (IsA(con, Const) && con->constisnull) appendStringInfoString(buf, "NO VALUE"); else get_rule_expr((Node *) con, context, false); con = (Const *) lthird(xexpr->args); Assert(IsA(con, Const)); if (con->constisnull) /* suppress STANDALONE NO VALUE */ ; else { switch (DatumGetInt32(con->constvalue)) { case XML_STANDALONE_YES: appendStringInfoString(buf, ", STANDALONE YES"); break; case XML_STANDALONE_NO: appendStringInfoString(buf, ", STANDALONE NO"); break; case XML_STANDALONE_NO_VALUE: appendStringInfoString(buf, ", STANDALONE NO VALUE"); break; default: break; } } break; case IS_DOCUMENT: get_rule_expr_paren((Node *) xexpr->args, context, false, node); break; } } if (xexpr->op == IS_XMLSERIALIZE) appendStringInfo(buf, " AS %s", format_type_with_typemod(xexpr->type, xexpr->typmod)); if (xexpr->op == IS_DOCUMENT) appendStringInfoString(buf, " IS DOCUMENT"); else appendStringInfoChar(buf, ')'); } break; case T_NullTest: { NullTest *ntest = (NullTest *) node; if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren((Node *) ntest->arg, context, true, node); switch (ntest->nulltesttype) { case IS_NULL: appendStringInfoString(buf, " IS NULL"); break; case IS_NOT_NULL: appendStringInfoString(buf, " IS NOT NULL"); break; default: elog(ERROR, "unrecognized nulltesttype: %d", (int) ntest->nulltesttype); } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } break; case T_BooleanTest: { BooleanTest *btest = (BooleanTest *) node; if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren((Node *) btest->arg, context, false, node); switch (btest->booltesttype) { case IS_TRUE: appendStringInfoString(buf, " IS TRUE"); break; case IS_NOT_TRUE: appendStringInfoString(buf, " IS NOT TRUE"); break; case IS_FALSE: appendStringInfoString(buf, " IS FALSE"); break; case IS_NOT_FALSE: appendStringInfoString(buf, " IS NOT FALSE"); break; case IS_UNKNOWN: appendStringInfoString(buf, " IS UNKNOWN"); break; case IS_NOT_UNKNOWN: appendStringInfoString(buf, " IS NOT UNKNOWN"); break; default: elog(ERROR, "unrecognized booltesttype: %d", (int) btest->booltesttype); } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } break; case T_CoerceToDomain: { CoerceToDomain *ctest = (CoerceToDomain *) node; Node *arg = (Node *) ctest->arg; if (ctest->coercionformat == COERCE_IMPLICIT_CAST && !showimplicit) { /* don't show the implicit cast */ get_rule_expr(arg, context, false); } else { get_coercion_expr(arg, context, ctest->resulttype, ctest->resulttypmod, node); } } break; case T_CoerceToDomainValue: appendStringInfoString(buf, "VALUE"); break; case T_SetToDefault: appendStringInfoString(buf, "DEFAULT"); break; case T_CurrentOfExpr: { CurrentOfExpr *cexpr = (CurrentOfExpr *) node; if (cexpr->cursor_name) appendStringInfo(buf, "CURRENT OF %s", quote_identifier(cexpr->cursor_name)); else appendStringInfo(buf, "CURRENT OF $%d", cexpr->cursor_param); } break; case T_InferenceElem: { InferenceElem *iexpr = (InferenceElem *) node; bool varprefix = context->varprefix; bool need_parens; /* * InferenceElem can only refer to target relation, so a * prefix is never useful. */ context->varprefix = false; /* * Parenthesize the element unless it's a simple Var or a bare * function call. Follows pg_get_indexdef_worker(). */ need_parens = !IsA(iexpr->expr, Var); if (IsA(iexpr->expr, FuncExpr) && ((FuncExpr *) iexpr->expr)->funcformat == COERCE_EXPLICIT_CALL) need_parens = false; if (need_parens) appendStringInfoChar(buf, '('); get_rule_expr((Node *) iexpr->expr, context, false); if (need_parens) appendStringInfoChar(buf, ')'); context->varprefix = varprefix; if (iexpr->infercollid) appendStringInfo(buf, " COLLATE %s", generate_collation_name(iexpr->infercollid)); /* Add the operator class name, if not default */ if (iexpr->inferopclass) { Oid inferopclass = iexpr->inferopclass; Oid inferopcinputtype = get_opclass_input_type(iexpr->inferopclass); get_opclass_name(inferopclass, inferopcinputtype, buf); } } break; case T_List: { char *sep; ListCell *l; sep = ""; foreach(l, (List *) node) { appendStringInfoString(buf, sep); get_rule_expr((Node *) lfirst(l), context, showimplicit); sep = ", "; } } break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); break; } } /* * get_rule_expr_toplevel - Parse back a toplevel expression * * Same as get_rule_expr(), except that if the expr is just a Var, we pass * istoplevel = true not false to get_variable(). This causes whole-row Vars * to get printed with decoration that will prevent expansion of "*". * We need to use this in contexts such as ROW() and VALUES(), where the * parser would expand "foo.*" appearing at top level. (In principle we'd * use this in get_target_list() too, but that has additional worries about * whether to print AS, so it needs to invoke get_variable() directly anyway.) */ static void get_rule_expr_toplevel(Node *node, deparse_context *context, bool showimplicit) { if (node && IsA(node, Var)) (void) get_variable((Var *) node, 0, true, context); else get_rule_expr(node, context, showimplicit); } /* * get_oper_expr - Parse back an OpExpr node */ static void get_oper_expr(OpExpr *expr, deparse_context *context) { StringInfo buf = context->buf; Oid opno = expr->opno; List *args = expr->args; if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); if (list_length(args) == 2) { /* binary operator */ Node *arg1 = (Node *) linitial(args); Node *arg2 = (Node *) lsecond(args); get_rule_expr_paren(arg1, context, true, (Node *) expr); appendStringInfo(buf, " %s ", generate_operator_name(opno, exprType(arg1), exprType(arg2))); get_rule_expr_paren(arg2, context, true, (Node *) expr); } else { /* unary operator --- but which side? */ Node *arg = (Node *) linitial(args); HeapTuple tp; Form_pg_operator optup; tp = SearchSysCache1(OPEROID, ObjectIdGetDatum(opno)); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup failed for operator %u", opno); optup = (Form_pg_operator) GETSTRUCT(tp); switch (optup->oprkind) { case 'l': appendStringInfo(buf, "%s ", generate_operator_name(opno, InvalidOid, exprType(arg))); get_rule_expr_paren(arg, context, true, (Node *) expr); break; case 'r': get_rule_expr_paren(arg, context, true, (Node *) expr); appendStringInfo(buf, " %s", generate_operator_name(opno, exprType(arg), InvalidOid)); break; default: elog(ERROR, "bogus oprkind: %d", optup->oprkind); } ReleaseSysCache(tp); } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } /* * get_func_expr - Parse back a FuncExpr node */ static void get_func_expr(FuncExpr *expr, deparse_context *context, bool showimplicit) { StringInfo buf = context->buf; Oid funcoid = expr->funcid; Oid argtypes[FUNC_MAX_ARGS]; int nargs; List *argnames; bool use_variadic; ListCell *l; /* * If the function call came from an implicit coercion, then just show the * first argument --- unless caller wants to see implicit coercions. */ if (expr->funcformat == COERCE_IMPLICIT_CAST && !showimplicit) { get_rule_expr_paren((Node *) linitial(expr->args), context, false, (Node *) expr); return; } /* * If the function call came from a cast, then show the first argument * plus an explicit cast operation. */ if (expr->funcformat == COERCE_EXPLICIT_CAST || expr->funcformat == COERCE_IMPLICIT_CAST) { Node *arg = linitial(expr->args); Oid rettype = expr->funcresulttype; int32 coercedTypmod; /* Get the typmod if this is a length-coercion function */ (void) exprIsLengthCoercion((Node *) expr, &coercedTypmod); get_coercion_expr(arg, context, rettype, coercedTypmod, (Node *) expr); return; } /* * Normal function: display as proname(args). First we need to extract * the argument datatypes. */ if (list_length(expr->args) > FUNC_MAX_ARGS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ARGUMENTS), errmsg("too many arguments"))); nargs = 0; argnames = NIL; foreach(l, expr->args) { Node *arg = (Node *) lfirst(l); if (IsA(arg, NamedArgExpr)) argnames = lappend(argnames, ((NamedArgExpr *) arg)->name); argtypes[nargs] = exprType(arg); nargs++; } appendStringInfo(buf, "%s(", generate_function_name(funcoid, nargs, argnames, argtypes, expr->funcvariadic, &use_variadic, context->special_exprkind)); nargs = 0; foreach(l, expr->args) { if (nargs++ > 0) appendStringInfoString(buf, ", "); if (use_variadic && lnext(l) == NULL) appendStringInfoString(buf, "VARIADIC "); get_rule_expr((Node *) lfirst(l), context, true); } appendStringInfoChar(buf, ')'); } /* * get_agg_expr - Parse back an Aggref node */ static void get_agg_expr(Aggref *aggref, deparse_context *context) { StringInfo buf = context->buf; Oid argtypes[FUNC_MAX_ARGS]; int nargs; bool use_variadic; /* Extract the argument types as seen by the parser */ nargs = get_aggregate_argtypes(aggref, argtypes); /* Print the aggregate name, schema-qualified if needed */ appendStringInfo(buf, "%s(%s", generate_function_name(aggref->aggfnoid, nargs, NIL, argtypes, aggref->aggvariadic, &use_variadic, context->special_exprkind), (aggref->aggdistinct != NIL) ? "DISTINCT " : ""); if (AGGKIND_IS_ORDERED_SET(aggref->aggkind)) { /* * Ordered-set aggregates do not use "*" syntax. Also, we needn't * worry about inserting VARIADIC. So we can just dump the direct * args as-is. */ Assert(!aggref->aggvariadic); get_rule_expr((Node *) aggref->aggdirectargs, context, true); Assert(aggref->aggorder != NIL); appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY "); get_rule_orderby(aggref->aggorder, aggref->args, false, context); } else { /* aggstar can be set only in zero-argument aggregates */ if (aggref->aggstar) appendStringInfoChar(buf, '*'); else { ListCell *l; int i; i = 0; foreach(l, aggref->args) { TargetEntry *tle = (TargetEntry *) lfirst(l); Node *arg = (Node *) tle->expr; Assert(!IsA(arg, NamedArgExpr)); if (tle->resjunk) continue; if (i++ > 0) appendStringInfoString(buf, ", "); if (use_variadic && i == nargs) appendStringInfoString(buf, "VARIADIC "); get_rule_expr(arg, context, true); } } if (aggref->aggorder != NIL) { appendStringInfoString(buf, " ORDER BY "); get_rule_orderby(aggref->aggorder, aggref->args, false, context); } } if (aggref->aggfilter != NULL) { appendStringInfoString(buf, ") FILTER (WHERE "); get_rule_expr((Node *) aggref->aggfilter, context, false); } appendStringInfoChar(buf, ')'); } /* * get_windowfunc_expr - Parse back a WindowFunc node */ static void get_windowfunc_expr(WindowFunc *wfunc, deparse_context *context) { StringInfo buf = context->buf; Oid argtypes[FUNC_MAX_ARGS]; int nargs; List *argnames; ListCell *l; if (list_length(wfunc->args) > FUNC_MAX_ARGS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ARGUMENTS), errmsg("too many arguments"))); nargs = 0; argnames = NIL; foreach(l, wfunc->args) { Node *arg = (Node *) lfirst(l); if (IsA(arg, NamedArgExpr)) argnames = lappend(argnames, ((NamedArgExpr *) arg)->name); argtypes[nargs] = exprType(arg); nargs++; } appendStringInfo(buf, "%s(", generate_function_name(wfunc->winfnoid, nargs, argnames, argtypes, false, NULL, context->special_exprkind)); /* winstar can be set only in zero-argument aggregates */ if (wfunc->winstar) appendStringInfoChar(buf, '*'); else get_rule_expr((Node *) wfunc->args, context, true); if (wfunc->aggfilter != NULL) { appendStringInfoString(buf, ") FILTER (WHERE "); get_rule_expr((Node *) wfunc->aggfilter, context, false); } appendStringInfoString(buf, ") OVER "); foreach(l, context->windowClause) { WindowClause *wc = (WindowClause *) lfirst(l); if (wc->winref == wfunc->winref) { if (wc->name) appendStringInfoString(buf, quote_identifier(wc->name)); else get_rule_windowspec(wc, context->windowTList, context); break; } } if (l == NULL) { if (context->windowClause) elog(ERROR, "could not find window clause for winref %u", wfunc->winref); /* * In EXPLAIN, we don't have window context information available, so * we have to settle for this: */ appendStringInfoString(buf, "(?)"); } } /* ---------- * get_coercion_expr * * Make a string representation of a value coerced to a specific type * ---------- */ static void get_coercion_expr(Node *arg, deparse_context *context, Oid resulttype, int32 resulttypmod, Node *parentNode) { StringInfo buf = context->buf; /* * Since parse_coerce.c doesn't immediately collapse application of * length-coercion functions to constants, what we'll typically see in * such cases is a Const with typmod -1 and a length-coercion function * right above it. Avoid generating redundant output. However, beware of * suppressing casts when the user actually wrote something like * 'foo'::text::char(3). * * Note: it might seem that we are missing the possibility of needing to * print a COLLATE clause for such a Const. However, a Const could only * have nondefault collation in a post-constant-folding tree, in which the * length coercion would have been folded too. See also the special * handling of CollateExpr in coerce_to_target_type(): any collation * marking will be above the coercion node, not below it. */ if (arg && IsA(arg, Const) && ((Const *) arg)->consttype == resulttype && ((Const *) arg)->consttypmod == -1) { /* Show the constant without normal ::typename decoration */ get_const_expr((Const *) arg, context, -1); } else { if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren(arg, context, false, parentNode); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } appendStringInfo(buf, "::%s", format_type_with_typemod(resulttype, resulttypmod)); } /* ---------- * get_const_expr * * Make a string representation of a Const * * showtype can be -1 to never show "::typename" decoration, or +1 to always * show it, or 0 to show it only if the constant wouldn't be assumed to be * the right type by default. * * If the Const's collation isn't default for its type, show that too. * We mustn't do this when showtype is -1 (since that means the caller will * print "::typename", and we can't put a COLLATE clause in between). It's * caller's responsibility that collation isn't missed in such cases. * ---------- */ static void get_const_expr(Const *constval, deparse_context *context, int showtype) { StringInfo buf = context->buf; Oid typoutput; bool typIsVarlena; char *extval; bool needlabel = false; if (constval->constisnull) { /* * Always label the type of a NULL constant to prevent misdecisions * about type when reparsing. */ appendStringInfoString(buf, "NULL"); if (showtype >= 0) { appendStringInfo(buf, "::%s", format_type_with_typemod(constval->consttype, constval->consttypmod)); get_const_collation(constval, context); } return; } getTypeOutputInfo(constval->consttype, &typoutput, &typIsVarlena); extval = OidOutputFunctionCall(typoutput, constval->constvalue); switch (constval->consttype) { case INT4OID: /* * INT4 can be printed without any decoration, unless it is * negative; in that case print it as '-nnn'::integer to ensure * that the output will re-parse as a constant, not as a constant * plus operator. In most cases we could get away with printing * (-nnn) instead, because of the way that gram.y handles negative * literals; but that doesn't work for INT_MIN, and it doesn't * seem that much prettier anyway. */ if (extval[0] != '-') appendStringInfoString(buf, extval); else { appendStringInfo(buf, "'%s'", extval); needlabel = true; /* we must attach a cast */ } break; case NUMERICOID: /* * NUMERIC can be printed without quotes if it looks like a float * constant (not an integer, and not Infinity or NaN) and doesn't * have a leading sign (for the same reason as for INT4). */ if (isdigit((unsigned char) extval[0]) && strcspn(extval, "eE.") != strlen(extval)) { appendStringInfoString(buf, extval); } else { appendStringInfo(buf, "'%s'", extval); needlabel = true; /* we must attach a cast */ } break; case BITOID: case VARBITOID: appendStringInfo(buf, "B'%s'", extval); break; case BOOLOID: if (strcmp(extval, "t") == 0) appendStringInfoString(buf, "true"); else appendStringInfoString(buf, "false"); break; default: simple_quote_literal(buf, extval); break; } pfree(extval); if (showtype < 0) return; /* * For showtype == 0, append ::typename unless the constant will be * implicitly typed as the right type when it is read in. * * XXX this code has to be kept in sync with the behavior of the parser, * especially make_const. */ switch (constval->consttype) { case BOOLOID: case UNKNOWNOID: /* These types can be left unlabeled */ needlabel = false; break; case INT4OID: /* We determined above whether a label is needed */ break; case NUMERICOID: /* * Float-looking constants will be typed as numeric, which we * checked above; but if there's a nondefault typmod we need to * show it. */ needlabel |= (constval->consttypmod >= 0); break; default: needlabel = true; break; } if (needlabel || showtype > 0) appendStringInfo(buf, "::%s", format_type_with_typemod(constval->consttype, constval->consttypmod)); get_const_collation(constval, context); } /* * helper for get_const_expr: append COLLATE if needed */ static void get_const_collation(Const *constval, deparse_context *context) { StringInfo buf = context->buf; if (OidIsValid(constval->constcollid)) { Oid typcollation = get_typcollation(constval->consttype); if (constval->constcollid != typcollation) { appendStringInfo(buf, " COLLATE %s", generate_collation_name(constval->constcollid)); } } } /* * simple_quote_literal - Format a string as a SQL literal, append to buf */ static void simple_quote_literal(StringInfo buf, const char *val) { const char *valptr; /* * We form the string literal according to the prevailing setting of * standard_conforming_strings; we never use E''. User is responsible for * making sure result is used correctly. */ appendStringInfoChar(buf, '\''); for (valptr = val; *valptr; valptr++) { char ch = *valptr; if (SQL_STR_DOUBLE(ch, !standard_conforming_strings)) appendStringInfoChar(buf, ch); appendStringInfoChar(buf, ch); } appendStringInfoChar(buf, '\''); } /* ---------- * get_sublink_expr - Parse back a sublink * ---------- */ static void get_sublink_expr(SubLink *sublink, deparse_context *context) { StringInfo buf = context->buf; Query *query = (Query *) (sublink->subselect); char *opname = NULL; bool need_paren; if (sublink->subLinkType == ARRAY_SUBLINK) appendStringInfoString(buf, "ARRAY("); else appendStringInfoChar(buf, '('); /* * Note that we print the name of only the first operator, when there are * multiple combining operators. This is an approximation that could go * wrong in various scenarios (operators in different schemas, renamed * operators, etc) but there is not a whole lot we can do about it, since * the syntax allows only one operator to be shown. */ if (sublink->testexpr) { if (IsA(sublink->testexpr, OpExpr)) { /* single combining operator */ OpExpr *opexpr = (OpExpr *) sublink->testexpr; get_rule_expr(linitial(opexpr->args), context, true); opname = generate_operator_name(opexpr->opno, exprType(linitial(opexpr->args)), exprType(lsecond(opexpr->args))); } else if (IsA(sublink->testexpr, BoolExpr)) { /* multiple combining operators, = or <> cases */ char *sep; ListCell *l; appendStringInfoChar(buf, '('); sep = ""; foreach(l, ((BoolExpr *) sublink->testexpr)->args) { OpExpr *opexpr = (OpExpr *) lfirst(l); Assert(IsA(opexpr, OpExpr)); appendStringInfoString(buf, sep); get_rule_expr(linitial(opexpr->args), context, true); if (!opname) opname = generate_operator_name(opexpr->opno, exprType(linitial(opexpr->args)), exprType(lsecond(opexpr->args))); sep = ", "; } appendStringInfoChar(buf, ')'); } else if (IsA(sublink->testexpr, RowCompareExpr)) { /* multiple combining operators, < <= > >= cases */ RowCompareExpr *rcexpr = (RowCompareExpr *) sublink->testexpr; appendStringInfoChar(buf, '('); get_rule_expr((Node *) rcexpr->largs, context, true); opname = generate_operator_name(linitial_oid(rcexpr->opnos), exprType(linitial(rcexpr->largs)), exprType(linitial(rcexpr->rargs))); appendStringInfoChar(buf, ')'); } else elog(ERROR, "unrecognized testexpr type: %d", (int) nodeTag(sublink->testexpr)); } need_paren = true; switch (sublink->subLinkType) { case EXISTS_SUBLINK: appendStringInfoString(buf, "EXISTS "); break; case ANY_SUBLINK: if (strcmp(opname, "=") == 0) /* Represent = ANY as IN */ appendStringInfoString(buf, " IN "); else appendStringInfo(buf, " %s ANY ", opname); break; case ALL_SUBLINK: appendStringInfo(buf, " %s ALL ", opname); break; case ROWCOMPARE_SUBLINK: appendStringInfo(buf, " %s ", opname); break; case EXPR_SUBLINK: case MULTIEXPR_SUBLINK: case ARRAY_SUBLINK: need_paren = false; break; case CTE_SUBLINK: /* shouldn't occur in a SubLink */ default: elog(ERROR, "unrecognized sublink type: %d", (int) sublink->subLinkType); break; } if (need_paren) appendStringInfoChar(buf, '('); get_query_def(query, buf, context->namespaces, NULL, context->prettyFlags, context->wrapColumn, context->indentLevel); if (need_paren) appendStringInfoString(buf, "))"); else appendStringInfoChar(buf, ')'); } /* ---------- * get_from_clause - Parse back a FROM clause * * "prefix" is the keyword that denotes the start of the list of FROM * elements. It is FROM when used to parse back SELECT and UPDATE, but * is USING when parsing back DELETE. * ---------- */ static void get_from_clause(Query *query, const char *prefix, deparse_context *context) { StringInfo buf = context->buf; bool first = true; ListCell *l; /* * We use the query's jointree as a guide to what to print. However, we * must ignore auto-added RTEs that are marked not inFromCl. (These can * only appear at the top level of the jointree, so it's sufficient to * check here.) This check also ensures we ignore the rule pseudo-RTEs * for NEW and OLD. */ foreach(l, query->jointree->fromlist) { Node *jtnode = (Node *) lfirst(l); if (IsA(jtnode, RangeTblRef)) { int varno = ((RangeTblRef *) jtnode)->rtindex; RangeTblEntry *rte = rt_fetch(varno, query->rtable); if (!rte->inFromCl) continue; } if (first) { appendContextKeyword(context, prefix, -PRETTYINDENT_STD, PRETTYINDENT_STD, 2); first = false; get_from_clause_item(jtnode, query, context); } else { StringInfoData itembuf; appendStringInfoString(buf, ", "); /* * Put the new FROM item's text into itembuf so we can decide * after we've got it whether or not it needs to go on a new line. */ initStringInfo(&itembuf); context->buf = &itembuf; get_from_clause_item(jtnode, query, context); /* Restore context's output buffer */ context->buf = buf; /* Consider line-wrapping if enabled */ if (PRETTY_INDENT(context) && context->wrapColumn >= 0) { /* Does the new item start with a new line? */ if (itembuf.len > 0 && itembuf.data[0] == '\n') { /* If so, we shouldn't add anything */ /* instead, remove any trailing spaces currently in buf */ removeStringInfoSpaces(buf); } else { char *trailing_nl; /* Locate the start of the current line in the buffer */ trailing_nl = strrchr(buf->data, '\n'); if (trailing_nl == NULL) trailing_nl = buf->data; else trailing_nl++; /* * Add a newline, plus some indentation, if the new item * would cause an overflow. */ if (strlen(trailing_nl) + itembuf.len > context->wrapColumn) appendContextKeyword(context, "", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_VAR); } } /* Add the new item */ appendStringInfoString(buf, itembuf.data); /* clean up */ pfree(itembuf.data); } } } static void get_from_clause_item(Node *jtnode, Query *query, deparse_context *context) { StringInfo buf = context->buf; deparse_namespace *dpns = (deparse_namespace *) linitial(context->namespaces); if (IsA(jtnode, RangeTblRef)) { int varno = ((RangeTblRef *) jtnode)->rtindex; RangeTblEntry *rte = rt_fetch(varno, query->rtable); char *refname = get_rtable_name(varno, context); deparse_columns *colinfo = deparse_columns_fetch(varno, dpns); RangeTblFunction *rtfunc1 = NULL; bool printalias; if (rte->lateral) appendStringInfoString(buf, "LATERAL "); /* Print the FROM item proper */ switch (rte->rtekind) { case RTE_RELATION: /* Normal relation RTE */ appendStringInfo(buf, "%s%s", only_marker(rte), generate_relation_name(rte->relid, context->namespaces)); break; case RTE_SUBQUERY: /* Subquery RTE */ appendStringInfoChar(buf, '('); get_query_def(rte->subquery, buf, context->namespaces, NULL, context->prettyFlags, context->wrapColumn, context->indentLevel); appendStringInfoChar(buf, ')'); break; case RTE_FUNCTION: /* Function RTE */ rtfunc1 = (RangeTblFunction *) linitial(rte->functions); /* * Omit ROWS FROM() syntax for just one function, unless it * has both a coldeflist and WITH ORDINALITY. If it has both, * we must use ROWS FROM() syntax to avoid ambiguity about * whether the coldeflist includes the ordinality column. */ if (list_length(rte->functions) == 1 && (rtfunc1->funccolnames == NIL || !rte->funcordinality)) { get_rule_expr(rtfunc1->funcexpr, context, true); /* we'll print the coldeflist below, if it has one */ } else { bool all_unnest; ListCell *lc; /* * If all the function calls in the list are to unnest, * and none need a coldeflist, then collapse the list back * down to UNNEST(args). (If we had more than one * built-in unnest function, this would get more * difficult.) * * XXX This is pretty ugly, since it makes not-terribly- * future-proof assumptions about what the parser would do * with the output; but the alternative is to emit our * nonstandard ROWS FROM() notation for what might have * been a perfectly spec-compliant multi-argument * UNNEST(). */ all_unnest = true; foreach(lc, rte->functions) { RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc); if (!IsA(rtfunc->funcexpr, FuncExpr) || ((FuncExpr *) rtfunc->funcexpr)->funcid != F_ARRAY_UNNEST || rtfunc->funccolnames != NIL) { all_unnest = false; break; } } if (all_unnest) { List *allargs = NIL; foreach(lc, rte->functions) { RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc); List *args = ((FuncExpr *) rtfunc->funcexpr)->args; allargs = list_concat(allargs, list_copy(args)); } appendStringInfoString(buf, "UNNEST("); get_rule_expr((Node *) allargs, context, true); appendStringInfoChar(buf, ')'); } else { int funcno = 0; appendStringInfoString(buf, "ROWS FROM("); foreach(lc, rte->functions) { RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc); if (funcno > 0) appendStringInfoString(buf, ", "); get_rule_expr(rtfunc->funcexpr, context, true); if (rtfunc->funccolnames != NIL) { /* Reconstruct the column definition list */ appendStringInfoString(buf, " AS "); get_from_clause_coldeflist(rtfunc, NULL, context); } funcno++; } appendStringInfoChar(buf, ')'); } /* prevent printing duplicate coldeflist below */ rtfunc1 = NULL; } if (rte->funcordinality) appendStringInfoString(buf, " WITH ORDINALITY"); break; case RTE_VALUES: /* Values list RTE */ appendStringInfoChar(buf, '('); get_values_def(rte->values_lists, context); appendStringInfoChar(buf, ')'); break; case RTE_CTE: appendStringInfoString(buf, quote_identifier(rte->ctename)); break; default: elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind); break; } /* Print the relation alias, if needed */ printalias = false; if (rte->alias != NULL) { /* Always print alias if user provided one */ printalias = true; } else if (colinfo->printaliases) { /* Always print alias if we need to print column aliases */ printalias = true; } else if (rte->rtekind == RTE_RELATION) { /* * No need to print alias if it's same as relation name (this * would normally be the case, but not if set_rtable_names had to * resolve a conflict). */ if (strcmp(refname, get_relation_name(rte->relid)) != 0) printalias = true; } else if (rte->rtekind == RTE_FUNCTION) { /* * For a function RTE, always print alias. This covers possible * renaming of the function and/or instability of the * FigureColname rules for things that aren't simple functions. * Note we'd need to force it anyway for the columndef list case. */ printalias = true; } else if (rte->rtekind == RTE_VALUES) { /* Alias is syntactically required for VALUES */ printalias = true; } else if (rte->rtekind == RTE_CTE) { /* * No need to print alias if it's same as CTE name (this would * normally be the case, but not if set_rtable_names had to * resolve a conflict). */ if (strcmp(refname, rte->ctename) != 0) printalias = true; } if (printalias) appendStringInfo(buf, " %s", quote_identifier(refname)); /* Print the column definitions or aliases, if needed */ if (rtfunc1 && rtfunc1->funccolnames != NIL) { /* Reconstruct the columndef list, which is also the aliases */ get_from_clause_coldeflist(rtfunc1, colinfo, context); } else { /* Else print column aliases as needed */ get_column_alias_list(colinfo, context); } /* Tablesample clause must go after any alias */ if (rte->rtekind == RTE_RELATION && rte->tablesample) get_tablesample_def(rte->tablesample, context); } else if (IsA(jtnode, JoinExpr)) { JoinExpr *j = (JoinExpr *) jtnode; deparse_columns *colinfo = deparse_columns_fetch(j->rtindex, dpns); bool need_paren_on_right; need_paren_on_right = PRETTY_PAREN(context) && !IsA(j->rarg, RangeTblRef) && !(IsA(j->rarg, JoinExpr) &&((JoinExpr *) j->rarg)->alias != NULL); if (!PRETTY_PAREN(context) || j->alias != NULL) appendStringInfoChar(buf, '('); get_from_clause_item(j->larg, query, context); switch (j->jointype) { case JOIN_INNER: if (j->quals) appendContextKeyword(context, " JOIN ", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_JOIN); else appendContextKeyword(context, " CROSS JOIN ", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_JOIN); break; case JOIN_LEFT: appendContextKeyword(context, " LEFT JOIN ", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_JOIN); break; case JOIN_FULL: appendContextKeyword(context, " FULL JOIN ", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_JOIN); break; case JOIN_RIGHT: appendContextKeyword(context, " RIGHT JOIN ", -PRETTYINDENT_STD, PRETTYINDENT_STD, PRETTYINDENT_JOIN); break; default: elog(ERROR, "unrecognized join type: %d", (int) j->jointype); } if (need_paren_on_right) appendStringInfoChar(buf, '('); get_from_clause_item(j->rarg, query, context); if (need_paren_on_right) appendStringInfoChar(buf, ')'); if (j->usingClause) { ListCell *lc; bool first = true; appendStringInfoString(buf, " USING ("); /* Use the assigned names, not what's in usingClause */ foreach(lc, colinfo->usingNames) { char *colname = (char *) lfirst(lc); if (first) first = false; else appendStringInfoString(buf, ", "); appendStringInfoString(buf, quote_identifier(colname)); } appendStringInfoChar(buf, ')'); } else if (j->quals) { appendStringInfoString(buf, " ON "); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr(j->quals, context, false); if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); } if (!PRETTY_PAREN(context) || j->alias != NULL) appendStringInfoChar(buf, ')'); /* Yes, it's correct to put alias after the right paren ... */ if (j->alias != NULL) { appendStringInfo(buf, " %s", quote_identifier(j->alias->aliasname)); get_column_alias_list(colinfo, context); } } else elog(ERROR, "unrecognized node type: %d", (int) nodeTag(jtnode)); } /* * get_column_alias_list - print column alias list for an RTE * * Caller must already have printed the relation's alias name. */ static void get_column_alias_list(deparse_columns *colinfo, deparse_context *context) { StringInfo buf = context->buf; int i; bool first = true; /* Don't print aliases if not needed */ if (!colinfo->printaliases) return; for (i = 0; i < colinfo->num_new_cols; i++) { char *colname = colinfo->new_colnames[i]; if (first) { appendStringInfoChar(buf, '('); first = false; } else appendStringInfoString(buf, ", "); appendStringInfoString(buf, quote_identifier(colname)); } if (!first) appendStringInfoChar(buf, ')'); } /* * get_from_clause_coldeflist - reproduce FROM clause coldeflist * * When printing a top-level coldeflist (which is syntactically also the * relation's column alias list), use column names from colinfo. But when * printing a coldeflist embedded inside ROWS FROM(), we prefer to use the * original coldeflist's names, which are available in rtfunc->funccolnames. * Pass NULL for colinfo to select the latter behavior. * * The coldeflist is appended immediately (no space) to buf. Caller is * responsible for ensuring that an alias or AS is present before it. */ static void get_from_clause_coldeflist(RangeTblFunction *rtfunc, deparse_columns *colinfo, deparse_context *context) { StringInfo buf = context->buf; ListCell *l1; ListCell *l2; ListCell *l3; ListCell *l4; int i; appendStringInfoChar(buf, '('); /* there's no forfour(), so must chase one list the hard way */ i = 0; l4 = list_head(rtfunc->funccolnames); forthree(l1, rtfunc->funccoltypes, l2, rtfunc->funccoltypmods, l3, rtfunc->funccolcollations) { Oid atttypid = lfirst_oid(l1); int32 atttypmod = lfirst_int(l2); Oid attcollation = lfirst_oid(l3); char *attname; if (colinfo) attname = colinfo->colnames[i]; else attname = strVal(lfirst(l4)); Assert(attname); /* shouldn't be any dropped columns here */ if (i > 0) appendStringInfoString(buf, ", "); appendStringInfo(buf, "%s %s", quote_identifier(attname), format_type_with_typemod(atttypid, atttypmod)); if (OidIsValid(attcollation) && attcollation != get_typcollation(atttypid)) appendStringInfo(buf, " COLLATE %s", generate_collation_name(attcollation)); l4 = lnext(l4); i++; } appendStringInfoChar(buf, ')'); } /* * get_tablesample_def - print a TableSampleClause */ static void get_tablesample_def(TableSampleClause *tablesample, deparse_context *context) { StringInfo buf = context->buf; Oid argtypes[1]; int nargs; ListCell *l; /* * We should qualify the handler's function name if it wouldn't be * resolved by lookup in the current search path. */ argtypes[0] = INTERNALOID; appendStringInfo(buf, " TABLESAMPLE %s (", generate_function_name(tablesample->tsmhandler, 1, NIL, argtypes, false, NULL, EXPR_KIND_NONE)); nargs = 0; foreach(l, tablesample->args) { if (nargs++ > 0) appendStringInfoString(buf, ", "); get_rule_expr((Node *) lfirst(l), context, false); } appendStringInfoChar(buf, ')'); if (tablesample->repeatable != NULL) { appendStringInfoString(buf, " REPEATABLE ("); get_rule_expr((Node *) tablesample->repeatable, context, false); appendStringInfoChar(buf, ')'); } } /* * get_opclass_name - fetch name of an index operator class * * The opclass name is appended (after a space) to buf. * * Output is suppressed if the opclass is the default for the given * actual_datatype. (If you don't want this behavior, just pass * InvalidOid for actual_datatype.) */ static void get_opclass_name(Oid opclass, Oid actual_datatype, StringInfo buf) { HeapTuple ht_opc; Form_pg_opclass opcrec; char *opcname; char *nspname; ht_opc = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclass)); if (!HeapTupleIsValid(ht_opc)) elog(ERROR, "cache lookup failed for opclass %u", opclass); opcrec = (Form_pg_opclass) GETSTRUCT(ht_opc); if (!OidIsValid(actual_datatype) || GetDefaultOpClass(actual_datatype, opcrec->opcmethod) != opclass) { /* Okay, we need the opclass name. Do we need to qualify it? */ opcname = NameStr(opcrec->opcname); if (OpclassIsVisible(opclass)) appendStringInfo(buf, " %s", quote_identifier(opcname)); else { nspname = get_namespace_name(opcrec->opcnamespace); appendStringInfo(buf, " %s.%s", quote_identifier(nspname), quote_identifier(opcname)); } } ReleaseSysCache(ht_opc); } /* * processIndirection - take care of array and subfield assignment * * We strip any top-level FieldStore or assignment ArrayRef nodes that * appear in the input, and return the subexpression that's to be assigned. * If printit is true, we also print out the appropriate decoration for the * base column name (that the caller just printed). */ static Node * processIndirection(Node *node, deparse_context *context, bool printit) { StringInfo buf = context->buf; for (;;) { if (node == NULL) break; if (IsA(node, FieldStore)) { FieldStore *fstore = (FieldStore *) node; Oid typrelid; char *fieldname; /* lookup tuple type */ typrelid = get_typ_typrelid(fstore->resulttype); if (!OidIsValid(typrelid)) elog(ERROR, "argument type %s of FieldStore is not a tuple type", format_type_be(fstore->resulttype)); /* * Print the field name. There should only be one target field in * stored rules. There could be more than that in executable * target lists, but this function cannot be used for that case. */ Assert(list_length(fstore->fieldnums) == 1); fieldname = get_relid_attribute_name(typrelid, linitial_int(fstore->fieldnums)); if (printit) appendStringInfo(buf, ".%s", quote_identifier(fieldname)); /* * We ignore arg since it should be an uninteresting reference to * the target column or subcolumn. */ node = (Node *) linitial(fstore->newvals); } else if (IsA(node, ArrayRef)) { ArrayRef *aref = (ArrayRef *) node; if (aref->refassgnexpr == NULL) break; if (printit) printSubscripts(aref, context); /* * We ignore refexpr since it should be an uninteresting reference * to the target column or subcolumn. */ node = (Node *) aref->refassgnexpr; } else break; } return node; } static void printSubscripts(ArrayRef *aref, deparse_context *context) { StringInfo buf = context->buf; ListCell *lowlist_item; ListCell *uplist_item; lowlist_item = list_head(aref->reflowerindexpr); /* could be NULL */ foreach(uplist_item, aref->refupperindexpr) { appendStringInfoChar(buf, '['); if (lowlist_item) { /* If subexpression is NULL, get_rule_expr prints nothing */ get_rule_expr((Node *) lfirst(lowlist_item), context, false); appendStringInfoChar(buf, ':'); lowlist_item = lnext(lowlist_item); } /* If subexpression is NULL, get_rule_expr prints nothing */ get_rule_expr((Node *) lfirst(uplist_item), context, false); appendStringInfoChar(buf, ']'); } } /* * quote_identifier - Quote an identifier only if needed * * When quotes are needed, we palloc the required space; slightly * space-wasteful but well worth it for notational simplicity. */ const char * quote_identifier(const char *ident) { /* * Can avoid quoting if ident starts with a lowercase letter or underscore * and contains only lowercase letters, digits, and underscores, *and* is * not any SQL keyword. Otherwise, supply quotes. */ int nquotes = 0; bool safe; const char *ptr; char *result; char *optr; /* * would like to use macros here, but they might yield unwanted * locale-specific results... */ safe = ((ident[0] >= 'a' && ident[0] <= 'z') || ident[0] == '_'); for (ptr = ident; *ptr; ptr++) { char ch = *ptr; if ((ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || (ch == '_')) { /* okay */ } else { safe = false; if (ch == '"') nquotes++; } } if (quote_all_identifiers) safe = false; if (safe) { /* * Check for keyword. We quote keywords except for unreserved ones. * (In some cases we could avoid quoting a col_name or type_func_name * keyword, but it seems much harder than it's worth to tell that.) * * Note: ScanKeywordLookup() does case-insensitive comparison, but * that's fine, since we already know we have all-lower-case. */ const ScanKeyword *keyword = ScanKeywordLookup(ident, ScanKeywords, NumScanKeywords); if (keyword != NULL && keyword->category != UNRESERVED_KEYWORD) safe = false; } if (safe) return ident; /* no change needed */ result = (char *) palloc(strlen(ident) + nquotes + 2 + 1); optr = result; *optr++ = '"'; for (ptr = ident; *ptr; ptr++) { char ch = *ptr; if (ch == '"') *optr++ = '"'; *optr++ = ch; } *optr++ = '"'; *optr = '\0'; return result; } /* * quote_qualified_identifier - Quote a possibly-qualified identifier * * Return a name of the form qualifier.ident, or just ident if qualifier * is NULL, quoting each component if necessary. The result is palloc'd. */ char * quote_qualified_identifier(const char *qualifier, const char *ident) { StringInfoData buf; initStringInfo(&buf); if (qualifier) appendStringInfo(&buf, "%s.", quote_identifier(qualifier)); appendStringInfoString(&buf, quote_identifier(ident)); return buf.data; } /* * get_relation_name * Get the unqualified name of a relation specified by OID * * This differs from the underlying get_rel_name() function in that it will * throw error instead of silently returning NULL if the OID is bad. */ static char * get_relation_name(Oid relid) { char *relname = get_rel_name(relid); if (!relname) elog(ERROR, "cache lookup failed for relation %u", relid); return relname; } /* * generate_relation_name * Compute the name to display for a relation specified by OID * * The result includes all necessary quoting and schema-prefixing. * * If namespaces isn't NIL, it must be a list of deparse_namespace nodes. * We will forcibly qualify the relation name if it equals any CTE name * visible in the namespace list. */ static char * generate_relation_name(Oid relid, List *namespaces) { HeapTuple tp; Form_pg_class reltup; bool need_qual; ListCell *nslist; char *relname; char *nspname; char *result; tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup failed for relation %u", relid); reltup = (Form_pg_class) GETSTRUCT(tp); relname = NameStr(reltup->relname); /* Check for conflicting CTE name */ need_qual = false; foreach(nslist, namespaces) { deparse_namespace *dpns = (deparse_namespace *) lfirst(nslist); ListCell *ctlist; foreach(ctlist, dpns->ctes) { CommonTableExpr *cte = (CommonTableExpr *) lfirst(ctlist); if (strcmp(cte->ctename, relname) == 0) { need_qual = true; break; } } if (need_qual) break; } /* Otherwise, qualify the name if not visible in search path */ if (!need_qual) need_qual = !RelationIsVisible(relid); if (need_qual) nspname = get_namespace_name(reltup->relnamespace); else nspname = NULL; result = quote_qualified_identifier(nspname, relname); ReleaseSysCache(tp); return result; } /* * generate_qualified_relation_name * Compute the name to display for a relation specified by OID * * As above, but unconditionally schema-qualify the name. */ static char * generate_qualified_relation_name(Oid relid) { HeapTuple tp; Form_pg_class reltup; char *relname; char *nspname; char *result; tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup failed for relation %u", relid); reltup = (Form_pg_class) GETSTRUCT(tp); relname = NameStr(reltup->relname); nspname = get_namespace_name(reltup->relnamespace); if (!nspname) elog(ERROR, "cache lookup failed for namespace %u", reltup->relnamespace); result = quote_qualified_identifier(nspname, relname); ReleaseSysCache(tp); return result; } /* * generate_function_name * Compute the name to display for a function specified by OID, * given that it is being called with the specified actual arg names and * types. (Those matter because of ambiguous-function resolution rules.) * * If we're dealing with a potentially variadic function (in practice, this * means a FuncExpr or Aggref, not some other way of calling a function), then * has_variadic must specify whether variadic arguments have been merged, * and *use_variadic_p will be set to indicate whether to print VARIADIC in * the output. For non-FuncExpr cases, has_variadic should be FALSE and * use_variadic_p can be NULL. * * The result includes all necessary quoting and schema-prefixing. */ static char * generate_function_name(Oid funcid, int nargs, List *argnames, Oid *argtypes, bool has_variadic, bool *use_variadic_p, ParseExprKind special_exprkind) { char *result; HeapTuple proctup; Form_pg_proc procform; char *proname; bool use_variadic; char *nspname; FuncDetailCode p_result; Oid p_funcid; Oid p_rettype; bool p_retset; int p_nvargs; Oid p_vatype; Oid *p_true_typeids; bool force_qualify = false; proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", funcid); procform = (Form_pg_proc) GETSTRUCT(proctup); proname = NameStr(procform->proname); /* * Due to parser hacks to avoid needing to reserve CUBE, we need to force * qualification in some special cases. */ if (special_exprkind == EXPR_KIND_GROUP_BY) { if (strcmp(proname, "cube") == 0 || strcmp(proname, "rollup") == 0) force_qualify = true; } /* * Determine whether VARIADIC should be printed. We must do this first * since it affects the lookup rules in func_get_detail(). * * Currently, we always print VARIADIC if the function has a merged * variadic-array argument. Note that this is always the case for * functions taking a VARIADIC argument type other than VARIADIC ANY. * * In principle, if VARIADIC wasn't originally specified and the array * actual argument is deconstructable, we could print the array elements * separately and not print VARIADIC, thus more nearly reproducing the * original input. For the moment that seems like too much complication * for the benefit, and anyway we do not know whether VARIADIC was * originally specified if it's a non-ANY type. */ if (use_variadic_p) { /* Parser should not have set funcvariadic unless fn is variadic */ Assert(!has_variadic || OidIsValid(procform->provariadic)); use_variadic = has_variadic; *use_variadic_p = use_variadic; } else { Assert(!has_variadic); use_variadic = false; } /* * The idea here is to schema-qualify only if the parser would fail to * resolve the correct function given the unqualified func name with the * specified argtypes and VARIADIC flag. But if we already decided to * force qualification, then we can skip the lookup and pretend we didn't * find it. */ if (!force_qualify) p_result = func_get_detail(list_make1(makeString(proname)), NIL, argnames, nargs, argtypes, !use_variadic, true, &p_funcid, &p_rettype, &p_retset, &p_nvargs, &p_vatype, &p_true_typeids, NULL); else { p_result = FUNCDETAIL_NOTFOUND; p_funcid = InvalidOid; } if ((p_result == FUNCDETAIL_NORMAL || p_result == FUNCDETAIL_AGGREGATE || p_result == FUNCDETAIL_WINDOWFUNC) && p_funcid == funcid) nspname = NULL; else nspname = get_namespace_name(procform->pronamespace); result = quote_qualified_identifier(nspname, proname); ReleaseSysCache(proctup); return result; } /* * generate_operator_name * Compute the name to display for an operator specified by OID, * given that it is being called with the specified actual arg types. * (Arg types matter because of ambiguous-operator resolution rules. * Pass InvalidOid for unused arg of a unary operator.) * * The result includes all necessary quoting and schema-prefixing, * plus the OPERATOR() decoration needed to use a qualified operator name * in an expression. */ static char * generate_operator_name(Oid operid, Oid arg1, Oid arg2) { StringInfoData buf; HeapTuple opertup; Form_pg_operator operform; char *oprname; char *nspname; Operator p_result; initStringInfo(&buf); opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(operid)); if (!HeapTupleIsValid(opertup)) elog(ERROR, "cache lookup failed for operator %u", operid); operform = (Form_pg_operator) GETSTRUCT(opertup); oprname = NameStr(operform->oprname); /* * The idea here is to schema-qualify only if the parser would fail to * resolve the correct operator given the unqualified op name with the * specified argtypes. */ switch (operform->oprkind) { case 'b': p_result = oper(NULL, list_make1(makeString(oprname)), arg1, arg2, true, -1); break; case 'l': p_result = left_oper(NULL, list_make1(makeString(oprname)), arg2, true, -1); break; case 'r': p_result = right_oper(NULL, list_make1(makeString(oprname)), arg1, true, -1); break; default: elog(ERROR, "unrecognized oprkind: %d", operform->oprkind); p_result = NULL; /* keep compiler quiet */ break; } if (p_result != NULL && oprid(p_result) == operid) nspname = NULL; else { nspname = get_namespace_name(operform->oprnamespace); appendStringInfo(&buf, "OPERATOR(%s.", quote_identifier(nspname)); } appendStringInfoString(&buf, oprname); if (nspname) appendStringInfoChar(&buf, ')'); if (p_result != NULL) ReleaseSysCache(p_result); ReleaseSysCache(opertup); return buf.data; } /* * generate_collation_name * Compute the name to display for a collation specified by OID * * The result includes all necessary quoting and schema-prefixing. */ char * generate_collation_name(Oid collid) { HeapTuple tp; Form_pg_collation colltup; char *collname; char *nspname; char *result; tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid)); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup failed for collation %u", collid); colltup = (Form_pg_collation) GETSTRUCT(tp); collname = NameStr(colltup->collname); if (!CollationIsVisible(collid)) nspname = get_namespace_name(colltup->collnamespace); else nspname = NULL; result = quote_qualified_identifier(nspname, collname); ReleaseSysCache(tp); return result; } /* * Given a C string, produce a TEXT datum. * * We assume that the input was palloc'd and may be freed. */ static text * string_to_text(char *str) { text *result; result = cstring_to_text(str); pfree(str); return result; } /* * Generate a C string representing a relation's reloptions, or NULL if none. */ static char * flatten_reloptions(Oid relid) { char *result = NULL; HeapTuple tuple; Datum reloptions; bool isnull; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); reloptions = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull); if (!isnull) { Datum sep, txt; /* * We want to use array_to_text(reloptions, ', ') --- but * DirectFunctionCall2(array_to_text) does not work, because * array_to_text() relies on flinfo to be valid. So use * OidFunctionCall2. */ sep = CStringGetTextDatum(", "); txt = OidFunctionCall2(F_ARRAY_TO_TEXT, reloptions, sep); result = TextDatumGetCString(txt); } ReleaseSysCache(tuple); return result; }