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postgresql/src/backend/utils/adt/ruleutils.c

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/*-------------------------------------------------------------------------
*
* ruleutils.c
* Functions to convert stored expressions/querytrees back to
* source text
*
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.313 2009/10/28 18:51:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#include <fcntl.h>
#include "access/genam.h"
#include "access/sysattr.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_authid.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 "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/tlist.h"
#include "parser/keywords.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/lsyscache.h"
#include "utils/tqual.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
#include "utils/xml.h"
/* ----------
* Pretty formatting constants
* ----------
*/
/* Indent counts */
#define PRETTYINDENT_STD 8
#define PRETTYINDENT_JOIN 13
#define PRETTYINDENT_JOIN_ON (PRETTYINDENT_JOIN-PRETTYINDENT_STD)
#define PRETTYINDENT_VAR 4
/* Pretty flags */
#define PRETTYFLAG_PAREN 1
#define PRETTYFLAG_INDENT 2
/* 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 indentLevel; /* current indent level for prettyprint */
bool varprefix; /* TRUE to print prefixes on Vars */
} 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.
*
* For deparsing plan trees, we provide for outer and inner subplan nodes.
* The tlists of these nodes are used to resolve OUTER and INNER varnos.
* Also, in the plan-tree case we don't have access to the parse-time CTE
* list, so we need a list of subplans instead.
*/
typedef struct
{
List *rtable; /* List of RangeTblEntry nodes */
List *ctes; /* List of CommonTableExpr nodes */
List *subplans; /* List of subplans, in plan-tree case */
Plan *outer_plan; /* OUTER subplan, or NULL if none */
Plan *inner_plan; /* INNER subplan, or NULL if none */
} deparse_namespace;
/* ----------
* 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";
/* ----------
* 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);
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,
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 make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags);
static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags);
static void get_query_def(Query *query, StringInfo buf, List *parentnamespace,
TupleDesc resultDesc, int prettyFlags, 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_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(SortGroupClause *srt, List *tlist,
bool force_colno,
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 void push_plan(deparse_namespace *dpns, Plan *subplan);
static char *get_variable(Var *var, int levelsup, bool showstar,
deparse_context *context);
static RangeTblEntry *find_rte_by_refname(const char *refname,
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 get_rule_expr(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 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_from_clause_alias(Alias *alias, RangeTblEntry *rte,
deparse_context *context);
static void get_from_clause_coldeflist(List *names, List *types, List *typmods,
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 *generate_relation_name(Oid relid, List *namespaces);
static char *generate_function_name(Oid funcid, int nargs, List *argnames,
Oid *argtypes, bool *is_variadic);
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);
PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, 0)));
}
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 : 0;
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);
plan_getrulebyoid = SPI_saveplan(plan);
}
/*
* Get the pg_rewrite tuple for this rule
*/
args[0] = ObjectIdGetDatum(ruleoid);
nulls[0] = ' ';
spirc = SPI_execute_plan(plan_getrulebyoid, args, nulls, true, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for rule %u", ruleoid);
if (SPI_processed != 1)
appendStringInfo(&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);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, 0)));
}
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 : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags)));
}
Datum
pg_get_viewdef_name(PG_FUNCTION_ARGS)
{
/* By qualified name */
text *viewname = PG_GETARG_TEXT_P(0);
RangeVar *viewrel;
Oid viewoid;
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname));
viewoid = RangeVarGetRelid(viewrel, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, 0)));
}
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 : 0;
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname));
viewoid = RangeVarGetRelid(viewrel, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags)));
}
/*
* Common code for by-OID and by-name variants of pg_get_viewdef
*/
static char *
pg_get_viewdef_worker(Oid viewoid, int prettyFlags)
{
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);
plan_getviewrule = SPI_saveplan(plan);
}
/*
* Get the pg_rewrite tuple for the view's SELECT rule
*/
args[0] = ObjectIdGetDatum(viewoid);
args[1] = PointerGetDatum(ViewSelectRuleName);
nulls[0] = ' ';
nulls[1] = ' ';
spirc = SPI_execute_plan(plan_getviewrule, args, nulls, true, 2);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for view %u", viewoid);
if (SPI_processed != 1)
appendStringInfo(&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);
}
/*
* 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;
/*
* 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,
SnapshotNow, 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",
trigrec->tgisconstraint ? "CONSTRAINT " : "",
quote_identifier(tgname));
appendStringInfoString(&buf, pretty ? "\n " : " ");
if (TRIGGER_FOR_BEFORE(trigrec->tgtype))
appendStringInfo(&buf, "BEFORE");
else
appendStringInfo(&buf, "AFTER");
if (TRIGGER_FOR_INSERT(trigrec->tgtype))
{
appendStringInfo(&buf, " INSERT");
findx++;
}
if (TRIGGER_FOR_DELETE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR DELETE");
else
appendStringInfo(&buf, " DELETE");
findx++;
}
if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR UPDATE");
else
appendStringInfo(&buf, " UPDATE");
/* 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)
appendStringInfo(&buf, " OR TRUNCATE");
else
appendStringInfo(&buf, " TRUNCATE");
}
appendStringInfo(&buf, " ON %s",
generate_relation_name(trigrec->tgrelid, NIL));
appendStringInfoString(&buf, pretty ? "\n " : " ");
if (trigrec->tgisconstraint)
{
if (trigrec->tgconstrrelid != InvalidOid)
{
appendStringInfo(&buf, "FROM %s",
generate_relation_name(trigrec->tgconstrrelid, NIL));
appendStringInfoString(&buf, pretty ? "\n " : " ");
}
if (!trigrec->tgdeferrable)
appendStringInfo(&buf, "NOT ");
appendStringInfo(&buf, "DEFERRABLE INITIALLY ");
if (trigrec->tginitdeferred)
appendStringInfo(&buf, "DEFERRED");
else
appendStringInfo(&buf, "IMMEDIATE");
appendStringInfoString(&buf, pretty ? "\n " : " ");
}
if (TRIGGER_FOR_ROW(trigrec->tgtype))
appendStringInfo(&buf, "FOR EACH ROW");
else
appendStringInfo(&buf, "FOR EACH STATEMENT");
appendStringInfoString(&buf, pretty ? "\n " : " ");
appendStringInfo(&buf, "EXECUTE PROCEDURE %s(",
generate_function_name(trigrec->tgfoid, 0,
NIL, NULL, NULL));
if (trigrec->tgnargs > 0)
{
bytea *val;
bool isnull;
char *p;
int i;
val = DatumGetByteaP(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(val);
for (i = 0; i < trigrec->tgnargs; i++)
{
if (i > 0)
appendStringInfo(&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 */
appendStringInfo(&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);
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0,
false, false, 0)));
}
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 : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno,
colno != 0,
false,
prettyFlags)));
}
/* Internal version that returns a palloc'd C string */
char *
pg_get_indexdef_string(Oid indexrelid)
{
return pg_get_indexdef_worker(indexrelid, 0, 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 : 0;
return pg_get_indexdef_worker(indexrelid, 0, true, false, prettyFlags);
}
static char *
pg_get_indexdef_worker(Oid indexrelid, int colno,
bool attrsOnly, bool showTblSpc,
int prettyFlags)
{
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;
Oid keycoltype;
Datum indclassDatum;
Datum indoptionDatum;
bool isnull;
oidvector *indclass;
int2vector *indoption;
StringInfoData buf;
char *str;
char *sep;
/*
* Fetch the pg_index tuple by the Oid of the index
*/
ht_idx = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexrelid),
0, 0, 0);
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 indclass and indoption the hard way */
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 = SearchSysCache(RELOID,
ObjectIdGetDatum(indexrelid),
0, 0, 0);
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 = SearchSysCache(AMOID,
ObjectIdGetDatum(idxrelrec->relam),
0, 0, 0);
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_rel_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)
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)));
/*
* Report the indexed attributes
*/
sep = "";
for (keyno = 0; keyno < idxrec->indnatts; keyno++)
{
AttrNumber attnum = idxrec->indkey.values[keyno];
int16 opt = indoption->values[keyno];
if (!colno)
appendStringInfoString(&buf, sep);
sep = ", ";
if (attnum != 0)
{
/* Simple index column */
char *attname;
attname = get_relid_attribute_name(indrelid, attnum);
if (!colno || colno == keyno + 1)
appendStringInfoString(&buf, quote_identifier(attname));
keycoltype = get_atttype(indrelid, attnum);
}
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);
}
if (!attrsOnly && (!colno || colno == keyno + 1))
{
/* 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)
{
appendStringInfo(&buf, " DESC");
/* NULLS FIRST is the default in this case */
if (!(opt & INDOPTION_NULLS_FIRST))
appendStringInfo(&buf, " NULLS LAST");
}
else
{
if (opt & INDOPTION_NULLS_FIRST)
appendStringInfo(&buf, " NULLS FIRST");
}
}
}
}
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))
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);
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 <constraintname>".
*/
Datum
pg_get_constraintdef(PG_FUNCTION_ARGS)
{
Oid constraintId = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false, 0)));
}
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 : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false, prettyFlags)));
}
/* Internal version that returns a palloc'd C string */
char *
pg_get_constraintdef_string(Oid constraintId)
{
return pg_get_constraintdef_worker(constraintId, true, 0);
}
static char *
pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
int prettyFlags)
{
HeapTuple tup;
Form_pg_constraint conForm;
StringInfoData buf;
tup = SearchSysCache(CONSTROID,
ObjectIdGetDatum(constraintId),
0, 0, 0);
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 && OidIsValid(conForm->conrelid))
{
appendStringInfo(&buf, "ALTER TABLE ONLY %s ADD CONSTRAINT %s ",
generate_relation_name(conForm->conrelid, NIL),
quote_identifier(NameStr(conForm->conname)));
}
switch (conForm->contype)
{
case CONSTRAINT_FOREIGN:
{
Datum val;
bool isnull;
const char *string;
/* Start off the constraint definition */
appendStringInfo(&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);
appendStringInfo(&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_UNSPECIFIED:
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)
appendStringInfo(&buf, "PRIMARY KEY (");
else
appendStringInfo(&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);
appendStringInfo(&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_rel_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. 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)", consrc);
break;
}
default:
elog(ERROR, "invalid constraint type \"%c\"", conForm->contype);
break;
}
if (conForm->condeferrable)
appendStringInfo(&buf, " DEFERRABLE");
if (conForm->condeferred)
appendStringInfo(&buf, " INITIALLY DEFERRED");
/* Cleanup */
ReleaseSysCache(tup);
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);
char *relname;
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, 0));
}
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 : 0;
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 = SearchSysCache(AUTHOID,
ObjectIdGetDatum(roleid),
0, 0, 0);
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;
/* Get the OID of the table */
tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename));
tableOid = RangeVarGetRelid(tablerv, 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,
SnapshotNow, 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))
{
HeapTuple classtup;
Form_pg_class classtuple;
char *nspname;
char *result;
/* Get the sequence's pg_class entry */
classtup = SearchSysCache(RELOID,
ObjectIdGetDatum(sequenceId),
0, 0, 0);
if (!HeapTupleIsValid(classtup))
elog(ERROR, "cache lookup failed for relation %u", sequenceId);
classtuple = (Form_pg_class) GETSTRUCT(classtup);
/* Get the namespace */
nspname = get_namespace_name(classtuple->relnamespace);
if (!nspname)
elog(ERROR, "cache lookup failed for namespace %u",
classtuple->relnamespace);
/* And construct the result string */
result = quote_qualified_identifier(nspname,
NameStr(classtuple->relname));
ReleaseSysCache(classtup);
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.
*/
Datum
pg_get_functiondef(PG_FUNCTION_ARGS)
{
Oid funcid = PG_GETARG_OID(0);
StringInfoData buf;
StringInfoData dq;
HeapTuple proctup;
HeapTuple langtup;
Form_pg_proc proc;
Form_pg_language lang;
Datum tmp;
bool isnull;
const char *prosrc;
const char *name;
const char *nsp;
float4 procost;
int oldlen;
initStringInfo(&buf);
/* Look up the function */
proctup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
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)));
/* Need its pg_language tuple for the language name */
langtup = SearchSysCache(LANGOID,
ObjectIdGetDatum(proc->prolang),
0, 0, 0);
if (!HeapTupleIsValid(langtup))
elog(ERROR, "cache lookup failed for language %u", proc->prolang);
lang = (Form_pg_language) GETSTRUCT(langtup);
/*
* 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);
appendStringInfo(&buf, "\n LANGUAGE %s\n",
quote_identifier(NameStr(lang->lanname)));
/* 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");
/* 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);
appendStringInfoString(&buf, "\n");
ReleaseSysCache(langtup);
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 = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
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 = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
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 = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
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)
appendStringInfoString(&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 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);
}
}
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)
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++;
}
return argsprinted;
}
/*
* 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.
*
* 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.indentLevel = startIndent;
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 *) palloc(sizeof(deparse_namespace));
/* Build a minimal RTE for the rel */
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = relid;
rte->eref = makeAlias(aliasname, NIL);
rte->inh = false;
rte->inFromCl = true;
/* Build one-element rtable */
dpns->rtable = list_make1(rte);
dpns->ctes = NIL;
dpns->subplans = NIL;
dpns->outer_plan = dpns->inner_plan = NULL;
/* Return a one-deep namespace stack */
return list_make1(dpns);
}
/*
* deparse_context_for_plan - Build deparse context for a plan node
*
* When deparsing an expression in a Plan tree, we might have to resolve
* OUTER or INNER references. To do this, the caller must provide the
* parent Plan node. In the normal case of a join plan node, OUTER and
* INNER references can be resolved by drilling down into the left and
* right child plans. A special case is that a nestloop inner indexscan
* might have OUTER Vars, but the outer side of the join is not a child
* plan node. To handle such cases the outer plan node must be passed
* separately. (Pass NULL for outer_plan otherwise.)
*
* Note: plan and outer_plan really ought to be declared as "Plan *", but
* we use "Node *" to avoid having to include plannodes.h in builtins.h.
*
* The plan's rangetable list must also be passed. We actually prefer to use
* the rangetable to resolve simple Vars, but the plan inputs are necessary
* for Vars that reference expressions computed in subplan target lists.
*
* We also need the list of subplans associated with the Plan tree; this
* is for resolving references to CTE subplans.
*/
List *
deparse_context_for_plan(Node *plan, Node *outer_plan,
List *rtable, List *subplans)
{
deparse_namespace *dpns;
dpns = (deparse_namespace *) palloc(sizeof(deparse_namespace));
dpns->rtable = rtable;
dpns->ctes = NIL;
dpns->subplans = subplans;
/*
* Set up outer_plan and inner_plan from the Plan node (this includes
* various special cases for particular Plan types).
*/
push_plan(dpns, (Plan *) plan);
/*
* If outer_plan is given, that overrides whatever we got from the plan.
*/
if (outer_plan)
dpns->outer_plan = (Plan *) outer_plan;
/* Return a one-deep namespace stack */
return list_make1(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;
int2 ev_attr;
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, "ev_attr");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_attr = DatumGetInt16(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':
appendStringInfo(buf, "SELECT");
break;
case '2':
appendStringInfo(buf, "UPDATE");
break;
case '3':
appendStringInfo(buf, "INSERT");
break;
case '4':
appendStringInfo(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 (ev_attr > 0)
appendStringInfo(buf, ".%s",
quote_identifier(get_relid_attribute_name(ev_class,
ev_attr)));
/* 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 ");
appendStringInfo(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);
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.indentLevel = PRETTYINDENT_STD;
dpns.rtable = query->rtable;
dpns.ctes = query->cteList;
dpns.subplans = NIL;
dpns.outer_plan = dpns.inner_plan = NULL;
get_rule_expr(qual, &context, false);
}
appendStringInfo(buf, " DO ");
/* The INSTEAD keyword (if so) */
if (is_instead)
appendStringInfo(buf, "INSTEAD ");
/* Finally the rules actions */
if (list_length(actions) > 1)
{
ListCell *action;
Query *query;
appendStringInfo(buf, "(");
foreach(action, actions)
{
query = (Query *) lfirst(action);
get_query_def(query, buf, NIL, NULL, prettyFlags, 0);
if (prettyFlags)
appendStringInfo(buf, ";\n");
else
appendStringInfo(buf, "; ");
}
appendStringInfo(buf, ");");
}
else if (list_length(actions) == 0)
{
appendStringInfo(buf, "NOTHING;");
}
else
{
Query *query;
query = (Query *) linitial(actions);
get_query_def(query, buf, NIL, NULL, prettyFlags, 0);
appendStringInfo(buf, ";");
}
}
/* ----------
* make_viewdef - reconstruct the SELECT part of a
* view rewrite rule
* ----------
*/
static void
make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags)
{
Query *query;
char ev_type;
Oid ev_class;
int2 ev_attr;
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, "ev_attr");
ev_attr = (int2) 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)
{
appendStringInfo(buf, "Not a view");
return;
}
query = (Query *) linitial(actions);
if (ev_type != '1' || ev_attr >= 0 || !is_instead ||
strcmp(ev_qual, "<>") != 0 || query->commandType != CMD_SELECT)
{
appendStringInfo(buf, "Not a view");
return;
}
ev_relation = heap_open(ev_class, AccessShareLock);
get_query_def(query, buf, NIL, RelationGetDescr(ev_relation),
prettyFlags, 0);
appendStringInfo(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 startIndent)
{
deparse_context context;
deparse_namespace dpns;
/*
* 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!
*/
AcquireRewriteLocks(query, 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.indentLevel = startIndent;
dpns.rtable = query->rtable;
dpns.ctes = query->cteList;
dpns.subplans = NIL;
dpns.outer_plan = dpns.inner_plan = NULL;
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:
appendStringInfo(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.
*/
get_rule_expr(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->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)
appendStringInfo(buf, "ALL");
else
get_rule_expr(query->limitCount, context, false);
}
/* Add FOR UPDATE/SHARE clauses if present */
if (query->hasForUpdate)
{
foreach(l, query->rowMarks)
{
RowMarkClause *rc = (RowMarkClause *) lfirst(l);
RangeTblEntry *rte = rt_fetch(rc->rti, query->rtable);
/* don't print implicit clauses */
if (rc->pushedDown)
continue;
if (rc->forUpdate)
appendContextKeyword(context, " FOR UPDATE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
else
appendContextKeyword(context, " FOR SHARE",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
appendStringInfo(buf, " OF %s",
quote_identifier(rte->eref->aliasname));
if (rc->noWait)
appendStringInfo(buf, " NOWAIT");
}
}
context->windowClause = save_windowclause;
context->windowTList = save_windowtlist;
}
static void
get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
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. If the jointree contains just a single VALUES RTE, we assume
* this case applies (without looking at the targetlist...)
*/
if (list_length(query->jointree->fromlist) == 1)
{
RangeTblRef *rtr = (RangeTblRef *) linitial(query->jointree->fromlist);
if (IsA(rtr, RangeTblRef))
{
RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable);
if (rte->rtekind == RTE_VALUES)
{
get_values_def(rte->values_lists, context);
return;
}
}
}
/*
* Build up the query string - first we say SELECT
*/
appendStringInfo(buf, "SELECT");
/* Add the DISTINCT clause if given */
if (query->distinctClause != NIL)
{
if (query->hasDistinctOn)
{
appendStringInfo(buf, " DISTINCT ON (");
sep = "";
foreach(l, query->distinctClause)
{
SortGroupClause *srt = (SortGroupClause *) lfirst(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(srt, query->targetList,
false, context);
sep = ", ";
}
appendStringInfo(buf, ")");
}
else
appendStringInfo(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)
{
appendContextKeyword(context, " GROUP BY ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
sep = "";
foreach(l, query->groupClause)
{
SortGroupClause *grp = (SortGroupClause *) lfirst(l);
appendStringInfoString(buf, sep);
get_rule_sortgroupclause(grp, query->targetList,
false, context);
sep = ", ";
}
}
/* 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;
char *sep;
int colno;
ListCell *l;
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++;
/*
* 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 want just "foo", instead.
*/
if (tle->expr && IsA(tle->expr, Var))
{
attname = get_variable((Var *) tle->expr, 0, false, 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(buf, " AS %s", quote_identifier(colname));
}
}
}
static void
get_setop_query(Node *setOp, Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
bool need_paren;
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->indentLevel);
if (need_paren)
appendStringInfoChar(buf, ')');
}
else if (IsA(setOp, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) setOp;
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoSpaces(buf, PRETTYINDENT_STD);
}
/*
* We force parens whenever nesting two SetOperationStmts. 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).
*/
need_paren = !IsA(op->larg, RangeTblRef);
if (need_paren)
appendStringInfoChar(buf, '(');
get_setop_query(op->larg, query, context, resultDesc);
if (need_paren)
appendStringInfoChar(buf, ')');
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
switch (op->op)
{
case SETOP_UNION:
appendContextKeyword(context, "UNION ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case SETOP_INTERSECT:
appendContextKeyword(context, "INTERSECT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case SETOP_EXCEPT:
appendContextKeyword(context, "EXCEPT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
default:
elog(ERROR, "unrecognized set op: %d",
(int) op->op);
}
if (op->all)
appendStringInfo(buf, "ALL ");
if (PRETTY_INDENT(context))
appendContextKeyword(context, "", 0, 0, 0);
need_paren = !IsA(op->rarg, RangeTblRef);
if (need_paren)
appendStringInfoChar(buf, '(');
get_setop_query(op->rarg, query, context, resultDesc);
if (need_paren)
appendStringInfoChar(buf, ')');
if (PRETTY_INDENT(context))
context->indentLevel -= PRETTYINDENT_STD;
}
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(SortGroupClause *srt, List *tlist, bool force_colno,
deparse_context *context)
{
StringInfo buf = context->buf;
TargetEntry *tle;
Node *expr;
tle = get_sortgroupclause_tle(srt, 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. Otherwise, just dump the expression
* normally.
*/
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
get_rule_expr(expr, context, true);
return expr;
}
/*
* 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, 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)
appendStringInfo(buf, " NULLS FIRST");
}
else if (srt->sortop == typentry->gt_opr)
{
appendStringInfo(buf, " DESC");
/* DESC defaults to NULLS FIRST */
if (!srt->nulls_first)
appendStringInfo(buf, " NULLS LAST");
}
else
{
appendStringInfo(buf, " USING %s",
generate_operator_name(srt->sortop,
sortcoltype,
sortcoltype));
/* be specific to eliminate ambiguity */
if (srt->nulls_first)
appendStringInfo(buf, " NULLS FIRST");
else
appendStringInfo(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, 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
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
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;
/*
* If it's an INSERT ... SELECT or VALUES (...), (...), ... there will be
* a single RTE for the SELECT or VALUES.
*/
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));
/*
* 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 = "";
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));
}
}
appendStringInfo(buf, ") ");
if (select_rte)
{
/* Add the SELECT */
get_query_def(select_rte->subquery, buf, NIL, NULL,
context->prettyFlags, context->indentLevel);
}
else if (values_rte)
{
/* A WITH clause is possible here */
get_with_clause(query, context);
/* Add the multi-VALUES expression lists */
get_values_def(values_rte->values_lists, context);
}
else
{
/* A WITH clause is possible here */
get_with_clause(query, context);
/* Add the single-VALUES expression list */
appendContextKeyword(context, "VALUES (",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
get_rule_expr((Node *) strippedexprs, context, false);
appendStringInfoChar(buf, ')');
}
/* 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;
char *sep;
RangeTblEntry *rte;
ListCell *l;
/*
* 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 ");
/* Add the comma separated list of 'attname = value' */
sep = "";
foreach(l, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *expr;
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.
*/
expr = processIndirection((Node *) tle->expr, context, true);
appendStringInfo(buf, " = ");
get_rule_expr(expr, context, false);
}
/* 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_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;
/*
* 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));
}
else
{
/* Currently only NOTIFY utility commands can appear in rules */
elog(ERROR, "unexpected utility statement type");
}
}
/*
* push_plan: set up deparse_namespace to recurse into the tlist of a subplan
*
* When expanding an OUTER or INNER reference, we must push new outer/inner
* subplans in case the referenced expression itself uses OUTER/INNER. 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 save and restore outer_plan and inner_plan around this.
*
* We also use this to initialize the fields during deparse_context_for_plan.
*/
static void
push_plan(deparse_namespace *dpns, Plan *subplan)
{
/*
* We special-case Append to pretend that the first child plan is the
* OUTER referent; we have to interpret OUTER Vars in the Append's tlist
* 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(subplan, Append))
dpns->outer_plan = (Plan *) linitial(((Append *) subplan)->appendplans);
else if (IsA(subplan, ModifyTable))
dpns->outer_plan = (Plan *) linitial(((ModifyTable *) subplan)->plans);
else
dpns->outer_plan = outerPlan(subplan);
/*
* 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.
*/
if (IsA(subplan, SubqueryScan))
dpns->inner_plan = ((SubqueryScan *) subplan)->subplan;
else if (IsA(subplan, CteScan))
{
int ctePlanId = ((CteScan *) subplan)->ctePlanId;
if (ctePlanId > 0 && ctePlanId <= list_length(dpns->subplans))
dpns->inner_plan = list_nth(dpns->subplans, ctePlanId - 1);
else
dpns->inner_plan = NULL;
}
else
dpns->inner_plan = innerPlan(subplan);
}
/*
* 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 showstar is TRUE, whole-row Vars are displayed as "foo.*";
* if FALSE, merely as "foo".
*
* Returns the attname of the Var, or NULL if not determinable.
*/
static char *
get_variable(Var *var, int levelsup, bool showstar, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *rte;
AttrNumber attnum;
int netlevelsup;
deparse_namespace *dpns;
char *schemaname;
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 or INNER, in which case we must dig down
* into the subplans.
*/
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 && dpns->outer_plan)
{
TargetEntry *tle;
Plan *save_outer;
Plan *save_inner;
tle = get_tle_by_resno(dpns->outer_plan->targetlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for OUTER var: %d", var->varattno);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->outer_plan);
/*
* 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, ')');
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
return NULL;
}
else if (var->varno == INNER && dpns->inner_plan)
{
TargetEntry *tle;
Plan *save_outer;
Plan *save_inner;
tle = get_tle_by_resno(dpns->inner_plan->targetlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INNER var: %d", var->varattno);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->inner_plan);
/*
* 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, ')');
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
return NULL;
}
else
{
elog(ERROR, "bogus varno: %d", var->varno);
return NULL; /* keep compiler quiet */
}
/* Identify names to use */
schemaname = NULL; /* default assumptions */
refname = rte->eref->aliasname;
/* Exceptions occur only if the RTE is alias-less */
if (rte->alias == NULL)
{
if (rte->rtekind == RTE_RELATION)
{
/*
* It's possible that use of the bare refname would find another
* more-closely-nested RTE, or be ambiguous, in which case we need
* to specify the schemaname to avoid these errors.
*/
if (find_rte_by_refname(rte->eref->aliasname, context) != rte)
schemaname = get_namespace_name(get_rel_namespace(rte->relid));
}
else if (rte->rtekind == RTE_JOIN)
{
/*
* 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. (This
* allows correct decompiling of cases where there are identically
* named columns on both sides of the join.) When it's not a
* simple reference, we have to just print the unqualified
* variable name (this can only happen with columns that were
* merged by USING or NATURAL clauses).
*
* 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->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);
if (IsA(aliasvar, Var))
{
return get_variable(aliasvar, var->varlevelsup + levelsup,
showstar, context);
}
}
/* Unnamed join has neither schemaname nor refname */
refname = NULL;
}
}
if (attnum == InvalidAttrNumber)
attname = NULL;
else
attname = get_rte_attribute_name(rte, attnum);
if (refname && (context->varprefix || attname == NULL))
{
if (schemaname)
appendStringInfo(buf, "%s.",
quote_identifier(schemaname));
if (strcmp(refname, "*NEW*") == 0)
appendStringInfoString(buf, "new");
else if (strcmp(refname, "*OLD*") == 0)
appendStringInfoString(buf, "old");
else
appendStringInfoString(buf, quote_identifier(refname));
if (attname || showstar)
appendStringInfoChar(buf, '.');
}
if (attname)
appendStringInfoString(buf, quote_identifier(attname));
else if (showstar)
appendStringInfoChar(buf, '*');
return attname;
}
/*
* Get the name of a field of an expression of composite type.
*
* This is fairly straightforward except for the case of a Var of type RECORD.
* Since no actual table or view column is allowed to have type RECORD, such
* a Var 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.
*
* levelsup is an extra offset to interpret the Var's varlevelsup correctly.
*/
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 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 or INNER, in which case we must dig down
* into the subplans.
*/
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 && dpns->outer_plan)
{
TargetEntry *tle;
Plan *save_outer;
Plan *save_inner;
const char *result;
tle = get_tle_by_resno(dpns->outer_plan->targetlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for OUTER var: %d", var->varattno);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->outer_plan);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
return result;
}
else if (var->varno == INNER && dpns->inner_plan)
{
TargetEntry *tle;
Plan *save_outer;
Plan *save_inner;
const char *result;
tle = get_tle_by_resno(dpns->inner_plan->targetlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for INNER var: %d", var->varattno);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->inner_plan);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
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_SPECIAL:
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;
mydpns.rtable = rte->subquery->rtable;
mydpns.ctes = rte->subquery->cteList;
mydpns.subplans = NIL;
mydpns.outer_plan = mydpns.inner_plan = NULL;
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;
Plan *save_outer;
Plan *save_inner;
const char *result;
if (!dpns->inner_plan)
elog(ERROR, "failed to find plan for subquery %s",
rte->eref->aliasname);
tle = get_tle_by_resno(dpns->inner_plan->targetlist,
attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->inner_plan);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
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);
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(ctequery->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 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;
mydpns.rtable = ctequery->rtable;
mydpns.ctes = ctequery->cteList;
mydpns.subplans = NIL;
mydpns.outer_plan = mydpns.inner_plan = NULL;
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;
Plan *save_outer;
Plan *save_inner;
const char *result;
if (!dpns->inner_plan)
elog(ERROR, "failed to find plan for CTE %s",
rte->eref->aliasname);
tle = get_tle_by_resno(dpns->inner_plan->targetlist,
attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
Assert(netlevelsup == 0);
save_outer = dpns->outer_plan;
save_inner = dpns->inner_plan;
push_plan(dpns, dpns->inner_plan);
result = get_name_for_var_field((Var *) tle->expr, fieldno,
levelsup, context);
dpns->outer_plan = save_outer;
dpns->inner_plan = save_inner;
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);
}
/*
* find_rte_by_refname - look up an RTE by refname in a deparse context
*
* Returns NULL if there is no matching RTE or the refname is ambiguous.
*
* NOTE: this code is not really correct since it does not take account of
* the fact that not all the RTEs in a rangetable may be visible from the
* point where a Var reference appears. For the purposes we need, however,
* the only consequence of a false match is that we might stick a schema
* qualifier on a Var that doesn't really need it. So it seems close
* enough.
*/
static RangeTblEntry *
find_rte_by_refname(const char *refname, deparse_context *context)
{
RangeTblEntry *result = NULL;
ListCell *nslist;
foreach(nslist, context->namespaces)
{
deparse_namespace *dpns = (deparse_namespace *) lfirst(nslist);
ListCell *rtlist;
foreach(rtlist, dpns->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rtlist);
if (strcmp(rte->eref->aliasname, refname) == 0)
{
if (result)
return NULL; /* it's ambiguous */
result = rte;
}
}
if (result)
break;
}
return result;
}
/*
* 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)
{
if (PRETTY_INDENT(context))
{
context->indentLevel += indentBefore;
appendStringInfoChar(context->buf, '\n');
appendStringInfoSpaces(context->buf,
Max(context->indentLevel, 0) + indentPlus);
appendStringInfoString(context->buf, str);
context->indentLevel += indentAfter;
if (context->indentLevel < 0)
context->indentLevel = 0;
}
else
appendStringInfoString(context->buf, str);
}
/*
* 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;
/*
* 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, true, context);
break;
case T_Const:
get_const_expr((Const *) node, context, 0);
break;
case T_Param:
appendStringInfo(buf, "$%d", ((Param *) node)->paramid);
break;
case T_Aggref:
get_agg_expr((Aggref *) node, context);
break;
case T_WindowFunc:
get_windowfunc_expr((WindowFunc *) node, context);
break;
case T_ArrayRef:
{
ArrayRef *aref = (ArrayRef *) node;
bool need_parens;
/*
* 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, ')');
printSubscripts(aref, context);
/*
* Array assignment nodes should have been handled in
* processIndirection().
*/
if (aref->refassgnexpr)
elog(ERROR, "unexpected refassgnexpr");
}
break;
case T_FuncExpr:
get_func_expr((FuncExpr *) node, context, showimplicit);
break;
case T_NamedArgExpr:
{
NamedArgExpr *na = (NamedArgExpr *) node;
get_rule_expr((Node *) na->arg, context, showimplicit);
appendStringInfo(buf, " AS %s", quote_identifier(na->name));
}
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);
appendStringInfo(buf, " IS DISTINCT FROM ");
get_rule_expr_paren(arg2, context, true, node);
if (!PRETTY_PAREN(context))
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_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)
{
appendStringInfo(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)
{
appendStringInfo(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, '(');
appendStringInfo(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 */
appendStringInfo(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
appendStringInfo(buf, "%s", splan->plan_name);
if (lnext(lc))
appendStringInfo(buf, " or ");
}
appendStringInfo(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:
/*
* We shouldn't see FieldStore here; it should have been stripped
* off by processIndirection().
*/
elog(ERROR, "unexpected FieldStore");
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_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 (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "WHEN ",
0, 0, 0);
if (caseexpr->arg)
{
/*
* The parser should have produced WHEN clauses of the
* form "CaseTestExpr = RHS"; we want to show just the
* RHS. If the user wrote something silly like "CASE
* boolexpr WHEN TRUE THEN ...", then the optimizer's
* simplify_boolean_equality() may have reduced this
* to just "CaseTestExpr" or "NOT CaseTestExpr", for
* which we have to show "TRUE" or "FALSE". Also,
* depending on context the original CaseTestExpr
* might have been reduced to a Const (but we won't
* see "WHEN Const"). We have also to consider the
* possibility that an implicit coercion was inserted
* between the CaseTestExpr and the operator.
*/
if (IsA(w, OpExpr))
{
List *args = ((OpExpr *) w)->args;
Node *lhs;
Node *rhs;
Assert(list_length(args) == 2);
lhs = strip_implicit_coercions(linitial(args));
Assert(IsA(lhs, CaseTestExpr) ||
IsA(lhs, Const));
rhs = (Node *) lsecond(args);
get_rule_expr(rhs, context, false);
}
else if (IsA(strip_implicit_coercions(w),
CaseTestExpr))
appendStringInfo(buf, "TRUE");
else if (not_clause(w))
{
Assert(IsA(strip_implicit_coercions((Node *) get_notclausearg((Expr *) w)),
CaseTestExpr));
appendStringInfo(buf, "FALSE");
}
else
elog(ERROR, "unexpected CASE WHEN clause: %d",
(int) nodeTag(w));
}
else
get_rule_expr(w, context, false);
appendStringInfo(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_ArrayExpr:
{
ArrayExpr *arrayexpr = (ArrayExpr *) node;
appendStringInfo(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.
*/
appendStringInfo(buf, "ROW(");
sep = "";
i = 0;
foreach(arg, rowexpr->args)
{
Node *e = (Node *) lfirst(arg);
if (tupdesc == NULL ||
!tupdesc->attrs[i]->attisdropped)
{
appendStringInfoString(buf, sep);
get_rule_expr(e, context, true);
sep = ", ";
}
i++;
}
if (tupdesc != NULL)
{
while (i < tupdesc->natts)
{
if (!tupdesc->attrs[i]->attisdropped)
{
appendStringInfoString(buf, sep);
appendStringInfo(buf, "NULL");
sep = ", ";
}
i++;
}
ReleaseTupleDesc(tupdesc);
}
appendStringInfo(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.
*/
appendStringInfo(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 = ", ";
}
appendStringInfo(buf, "))");
}
break;
case T_CoalesceExpr:
{
CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
appendStringInfo(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:
appendStringInfo(buf, "GREATEST(");
break;
case IS_LEAST:
appendStringInfo(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_NullIfExpr:
{
NullIfExpr *nullifexpr = (NullIfExpr *) node;
appendStringInfo(buf, "NULLIF(");
get_rule_expr((Node *) nullifexpr->args, context, true);
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:
appendStringInfo(buf, " IS NULL");
break;
case IS_NOT_NULL:
appendStringInfo(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:
appendStringInfo(buf, " IS TRUE");
break;
case IS_NOT_TRUE:
appendStringInfo(buf, " IS NOT TRUE");
break;
case IS_FALSE:
appendStringInfo(buf, " IS FALSE");
break;
case IS_NOT_FALSE:
appendStringInfo(buf, " IS NOT FALSE");
break;
case IS_UNKNOWN:
appendStringInfo(buf, " IS UNKNOWN");
break;
case IS_NOT_UNKNOWN:
appendStringInfo(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:
appendStringInfo(buf, "VALUE");
break;
case T_SetToDefault:
appendStringInfo(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_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_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 = SearchSysCache(OPEROID,
ObjectIdGetDatum(opno),
0, 0, 0);
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 is_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,
&is_variadic));
nargs = 0;
foreach(l, expr->args)
{
if (nargs++ > 0)
appendStringInfoString(buf, ", ");
if (is_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;
ListCell *l;
if (list_length(aggref->args) > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
errmsg("too many arguments")));
nargs = 0;
foreach(l, aggref->args)
{
Node *arg = (Node *) lfirst(l);
Assert(!IsA(arg, NamedArgExpr));
argtypes[nargs] = exprType(arg);
nargs++;
}
appendStringInfo(buf, "%s(%s",
generate_function_name(aggref->aggfnoid, nargs,
NIL, argtypes, NULL),
aggref->aggdistinct ? "DISTINCT " : "");
/* aggstar can be set only in zero-argument aggregates */
if (aggref->aggstar)
appendStringInfoChar(buf, '*');
else
get_rule_expr((Node *) aggref->args, context, true);
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;
ListCell *l;
if (list_length(wfunc->args) > FUNC_MAX_ARGS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
errmsg("too many arguments")));
nargs = 0;
foreach(l, wfunc->args)
{
Node *arg = (Node *) lfirst(l);
Assert(!IsA(arg, NamedArgExpr));
argtypes[nargs] = exprType(arg);
nargs++;
}
appendStringInfo(buf, "%s(",
generate_function_name(wfunc->winfnoid, nargs,
NIL, argtypes, NULL));
/* winstar can be set only in zero-argument aggregates */
if (wfunc->winstar)
appendStringInfoChar(buf, '*');
else
get_rule_expr((Node *) wfunc->args, context, true);
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).
*/
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.
* ----------
*/
static void
get_const_expr(Const *constval, deparse_context *context, int showtype)
{
StringInfo buf = context->buf;
Oid typoutput;
bool typIsVarlena;
char *extval;
bool isfloat = false;
bool needlabel;
if (constval->constisnull)
{
/*
* Always label the type of a NULL constant to prevent misdecisions
* about type when reparsing.
*/
appendStringInfo(buf, "NULL");
if (showtype >= 0)
appendStringInfo(buf, "::%s",
format_type_with_typemod(constval->consttype,
constval->consttypmod));
return;
}
getTypeOutputInfo(constval->consttype,
&typoutput, &typIsVarlena);
extval = OidOutputFunctionCall(typoutput, constval->constvalue);
switch (constval->consttype)
{
case INT2OID:
case INT4OID:
case INT8OID:
case OIDOID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
{
/*
* These types are printed without quotes unless they contain
* values that aren't accepted by the scanner unquoted (e.g.,
* 'NaN'). Note that strtod() and friends might accept NaN,
* so we can't use that to test.
*
* In reality we only need to defend against infinity and NaN,
* so we need not get too crazy about pattern matching here.
*
* There is a special-case gotcha: if the constant is signed,
* we need to parenthesize it, else the parser might see a
* leading plus/minus as binding less tightly than adjacent
* operators --- particularly, the cast that we might attach
* below.
*/
if (strspn(extval, "0123456789+-eE.") == strlen(extval))
{
if (extval[0] == '+' || extval[0] == '-')
appendStringInfo(buf, "(%s)", extval);
else
appendStringInfoString(buf, extval);
if (strcspn(extval, "eE.") != strlen(extval))
isfloat = true; /* it looks like a float */
}
else
appendStringInfo(buf, "'%s'", extval);
}
break;
case BITOID:
case VARBITOID:
appendStringInfo(buf, "B'%s'", extval);
break;
case BOOLOID:
if (strcmp(extval, "t") == 0)
appendStringInfo(buf, "true");
else
appendStringInfo(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 INT4OID:
case UNKNOWNOID:
/* These types can be left unlabeled */
needlabel = false;
break;
case NUMERICOID:
/*
* Float-looking constants will be typed as numeric, but if
* there's a specific typmod we need to show it.
*/
needlabel = !isfloat || (constval->consttypmod >= 0);
break;
default:
needlabel = true;
break;
}
if (needlabel || showtype > 0)
appendStringInfo(buf, "::%s",
format_type_with_typemod(constval->consttype,
constval->consttypmod));
}
/*
* 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)
appendStringInfo(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:
appendStringInfo(buf, "EXISTS ");
break;
case ANY_SUBLINK:
if (strcmp(opname, "=") == 0) /* Represent = ANY as IN */
appendStringInfo(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 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->indentLevel);
if (need_paren)
appendStringInfo(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;
}
else
appendStringInfoString(buf, ", ");
get_from_clause_item(jtnode, query, context);
}
}
static void
get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
bool gavealias = false;
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->indentLevel);
appendStringInfoChar(buf, ')');
break;
case RTE_FUNCTION:
/* Function RTE */
get_rule_expr(rte->funcexpr, context, true);
break;
case RTE_VALUES:
/* Values list RTE */
get_values_def(rte->values_lists, context);
break;
case RTE_CTE:
appendStringInfoString(buf, quote_identifier(rte->ctename));
break;
default:
elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind);
break;
}
if (rte->alias != NULL)
{
appendStringInfo(buf, " %s",
quote_identifier(rte->alias->aliasname));
gavealias = true;
}
else if (rte->rtekind == RTE_RELATION &&
strcmp(rte->eref->aliasname, get_rel_name(rte->relid)) != 0)
{
/*
* Apparently the rel has been renamed since the rule was made.
* Emit a fake alias clause so that variable references will still
* work. This is not a 100% solution but should work in most
* reasonable situations.
*/
appendStringInfo(buf, " %s",
quote_identifier(rte->eref->aliasname));
gavealias = true;
}
else if (rte->rtekind == RTE_FUNCTION)
{
/*
* For a function RTE, always give an alias. This covers possible
* renaming of the function and/or instability of the
* FigureColname rules for things that aren't simple functions.
*/
appendStringInfo(buf, " %s",
quote_identifier(rte->eref->aliasname));
gavealias = true;
}
if (rte->rtekind == RTE_FUNCTION)
{
if (rte->funccoltypes != NIL)
{
/* Function returning RECORD, reconstruct the columndefs */
if (!gavealias)
appendStringInfo(buf, " AS ");
get_from_clause_coldeflist(rte->eref->colnames,
rte->funccoltypes,
rte->funccoltypmods,
context);
}
else
{
/*
* 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).
*/
get_from_clause_alias(rte->eref, rte, context);
}
}
else
{
/*
* For non-function RTEs, just report whatever the user originally
* gave as column aliases.
*/
get_from_clause_alias(rte->alias, rte, context);
}
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
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);
if (j->isNatural)
{
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
switch (j->jointype)
{
case JOIN_INNER:
appendContextKeyword(context, "NATURAL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_LEFT:
appendContextKeyword(context, "NATURAL LEFT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_FULL:
appendContextKeyword(context, "NATURAL FULL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_RIGHT:
appendContextKeyword(context, "NATURAL RIGHT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
default:
elog(ERROR, "unrecognized join type: %d",
(int) j->jointype);
}
}
else
{
switch (j->jointype)
{
case JOIN_INNER:
if (j->quals)
appendContextKeyword(context, " JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
else
appendContextKeyword(context, " CROSS JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 1);
break;
case JOIN_LEFT:
appendContextKeyword(context, " LEFT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
case JOIN_FULL:
appendContextKeyword(context, " FULL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
case JOIN_RIGHT:
appendContextKeyword(context, " RIGHT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
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, ')');
context->indentLevel -= PRETTYINDENT_JOIN_ON;
if (!j->isNatural)
{
if (j->usingClause)
{
ListCell *col;
appendStringInfo(buf, " USING (");
foreach(col, j->usingClause)
{
if (col != list_head(j->usingClause))
appendStringInfo(buf, ", ");
appendStringInfoString(buf,
quote_identifier(strVal(lfirst(col))));
}
appendStringInfoChar(buf, ')');
}
else if (j->quals)
{
appendStringInfo(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_from_clause_alias(j->alias,
rt_fetch(j->rtindex, query->rtable),
context);
}
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
}
/*
* get_from_clause_alias - reproduce column alias list
*
* This is tricky because we must ignore dropped columns.
*/
static void
get_from_clause_alias(Alias *alias, RangeTblEntry *rte,
deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *col;
AttrNumber attnum;
bool first = true;
if (alias == NULL || alias->colnames == NIL)
return; /* definitely nothing to do */
attnum = 0;
foreach(col, alias->colnames)
{
attnum++;
if (get_rte_attribute_is_dropped(rte, attnum))
continue;
if (first)
{
appendStringInfoChar(buf, '(');
first = false;
}
else
appendStringInfo(buf, ", ");
appendStringInfoString(buf,
quote_identifier(strVal(lfirst(col))));
}
if (!first)
appendStringInfoChar(buf, ')');
}
/*
* get_from_clause_coldeflist - reproduce FROM clause coldeflist
*
* 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(List *names, List *types, List *typmods,
deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *l1;
ListCell *l2;
ListCell *l3;
int i = 0;
appendStringInfoChar(buf, '(');
l2 = list_head(types);
l3 = list_head(typmods);
foreach(l1, names)
{
char *attname = strVal(lfirst(l1));
Oid atttypid;
int32 atttypmod;
atttypid = lfirst_oid(l2);
l2 = lnext(l2);
atttypmod = lfirst_int(l3);
l3 = lnext(l3);
if (i > 0)
appendStringInfo(buf, ", ");
appendStringInfo(buf, "%s %s",
quote_identifier(attname),
format_type_with_typemod(atttypid, atttypmod));
i++;
}
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 = SearchSysCache(CLAOID,
ObjectIdGetDatum(opclass),
0, 0, 0);
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. Note we assume here that there's only
* one field being assigned to. This is okay in stored rules but
* could be wrong in executable target lists. Presently no
* problem since explain.c doesn't print plan targetlists, but
* someday may have to think of something ...
*/
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)
{
get_rule_expr((Node *) lfirst(lowlist_item), context, false);
appendStringInfoChar(buf, ':');
lowlist_item = lnext(lowlist_item);
}
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 <ctype.h> 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 (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;
}
/*
* 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 = SearchSysCache(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
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_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.)
*
* The result includes all necessary quoting and schema-prefixing. We can
* also pass back an indication of whether the function is variadic.
*/
static char *
generate_function_name(Oid funcid, int nargs, List *argnames,
Oid *argtypes, bool *is_variadic)
{
HeapTuple proctup;
Form_pg_proc procform;
char *proname;
char *nspname;
char *result;
FuncDetailCode p_result;
Oid p_funcid;
Oid p_rettype;
bool p_retset;
int p_nvargs;
Oid *p_true_typeids;
proctup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
procform = (Form_pg_proc) GETSTRUCT(proctup);
proname = NameStr(procform->proname);
/*
* 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. If the function is variadic, we should presume
* that VARIADIC will be included in the call.
*/
p_result = func_get_detail(list_make1(makeString(proname)),
NIL, argnames, nargs, argtypes,
!OidIsValid(procform->provariadic), true,
&p_funcid, &p_rettype,
&p_retset, &p_nvargs, &p_true_typeids, NULL);
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);
/* Check variadic-ness if caller cares */
if (is_variadic)
{
/* "any" variadics are not treated as variadics for listing */
if (OidIsValid(procform->provariadic) &&
procform->provariadic != ANYOID)
*is_variadic = true;
else
*is_variadic = false;
}
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 = SearchSysCache(OPEROID,
ObjectIdGetDatum(operid),
0, 0, 0);
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;
}
/*
* 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 = SearchSysCache(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
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;
}
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