/********************************************************************** * ruleutils.c - Functions to convert stored expressions/querytrees * back to source text * * IDENTIFICATION * $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.116 2002/08/16 23:01:19 tgl Exp $ * * This software is copyrighted by Jan Wieck - Hamburg. * * The author hereby grants permission to use, copy, modify, * distribute, and license this software and its documentation * for any purpose, provided that existing copyright notices are * retained in all copies and that this notice is included * verbatim in any distributions. No written agreement, license, * or royalty fee is required for any of the authorized uses. * Modifications to this software may be copyrighted by their * author and need not follow the licensing terms described * here, provided that the new terms are clearly indicated on * the first page of each file where they apply. * * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR * CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS * SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN * IF THE AUTHOR HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON * AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAVE NO * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, * ENHANCEMENTS, OR MODIFICATIONS. * **********************************************************************/ #include "postgres.h" #include #include #include "access/genam.h" #include "catalog/catname.h" #include "catalog/heap.h" #include "catalog/index.h" #include "catalog/indexing.h" #include "catalog/namespace.h" #include "catalog/pg_cast.h" #include "catalog/pg_constraint.h" #include "catalog/pg_index.h" #include "catalog/pg_opclass.h" #include "catalog/pg_operator.h" #include "catalog/pg_shadow.h" #include "executor/spi.h" #include "lib/stringinfo.h" #include "nodes/makefuncs.h" #include "optimizer/clauses.h" #include "optimizer/tlist.h" #include "parser/keywords.h" #include "parser/parse_expr.h" #include "parser/parse_func.h" #include "parser/parse_oper.h" #include "parser/parsetree.h" #include "rewrite/rewriteManip.h" #include "rewrite/rewriteSupport.h" #include "utils/array.h" #include "utils/fmgroids.h" #include "utils/lsyscache.h" /* ---------- * 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 */ 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. * * For deparsing plan trees, we allow two special RTE entries that are not * part of the rtable list (mainly because they don't have consecutively * allocated varnos). */ typedef struct { List *rtable; /* List of RangeTblEntry nodes */ int outer_varno; /* varno for outer_rte */ RangeTblEntry *outer_rte; /* special RangeTblEntry, or NULL */ int inner_varno; /* varno for inner_rte */ RangeTblEntry *inner_rte; /* special RangeTblEntry, or NULL */ } deparse_namespace; /* ---------- * Global data * ---------- */ static void *plan_getrulebyoid = NULL; static char *query_getrulebyoid = "SELECT * FROM pg_catalog.pg_rewrite WHERE oid = $1"; static void *plan_getviewrule = NULL; static 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 text *pg_do_getviewdef(Oid viewoid); static void decompile_column_index_array(Datum column_index_array, Oid relId, StringInfo buf); static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc); static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc); static void get_query_def(Query *query, StringInfo buf, List *parentnamespace, TupleDesc resultDesc); 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_setop_query(Node *setOp, Query *query, deparse_context *context, TupleDesc resultDesc); static Node *get_rule_sortgroupclause(SortClause *srt, List *tlist, bool force_colno, deparse_context *context); static void get_names_for_var(Var *var, deparse_context *context, char **schemaname, char **refname, char **attname); static RangeTblEntry *find_rte_by_refname(const char *refname, deparse_context *context); static void get_rule_expr(Node *node, deparse_context *context); static void get_oper_expr(Expr *expr, deparse_context *context); static void get_func_expr(Expr *expr, deparse_context *context); static void get_agg_expr(Aggref *aggref, deparse_context *context); static Node *strip_type_coercion(Node *expr, Oid resultType); static void get_tle_expr(TargetEntry *tle, deparse_context *context); static void get_const_expr(Const *constval, deparse_context *context); static void get_sublink_expr(Node *node, deparse_context *context); static void get_from_clause(Query *query, deparse_context *context); static void get_from_clause_item(Node *jtnode, Query *query, deparse_context *context); static void get_opclass_name(Oid opclass, Oid actual_datatype, StringInfo buf); static bool tleIsArrayAssign(TargetEntry *tle); static char *generate_relation_name(Oid relid); static char *generate_function_name(Oid funcid, int nargs, Oid *argtypes); static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2); static char *get_relid_attribute_name(Oid relid, AttrNumber attnum); #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); text *ruledef; Datum args[1]; char nulls[1]; int spirc; HeapTuple ruletup; TupleDesc rulettc; StringInfoData buf; int len; /* * Connect to SPI manager */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "get_ruledef: cannot connect to SPI manager"); /* * 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]; void *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_execp(plan_getrulebyoid, args, nulls, 1); if (spirc != SPI_OK_SELECT) elog(ERROR, "failed to get pg_rewrite tuple for %u", ruleoid); if (SPI_processed != 1) { if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "get_ruledef: SPI_finish() failed"); ruledef = palloc(VARHDRSZ + 1); VARATT_SIZEP(ruledef) = VARHDRSZ + 1; VARDATA(ruledef)[0] = '-'; PG_RETURN_TEXT_P(ruledef); } ruletup = SPI_tuptable->vals[0]; rulettc = SPI_tuptable->tupdesc; /* * Get the rules definition and put it into executors memory */ initStringInfo(&buf); make_ruledef(&buf, ruletup, rulettc); len = buf.len + VARHDRSZ; ruledef = SPI_palloc(len); VARATT_SIZEP(ruledef) = len; memcpy(VARDATA(ruledef), buf.data, buf.len); pfree(buf.data); /* * Disconnect from SPI manager */ if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "get_ruledef: SPI_finish() failed"); /* * Easy - isn't it? */ PG_RETURN_TEXT_P(ruledef); } /* ---------- * 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); text *ruledef; ruledef = pg_do_getviewdef(viewoid); PG_RETURN_TEXT_P(ruledef); } Datum pg_get_viewdef_name(PG_FUNCTION_ARGS) { /* By qualified name */ text *viewname = PG_GETARG_TEXT_P(0); RangeVar *viewrel; Oid viewoid; text *ruledef; viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname, "get_viewdef")); viewoid = RangeVarGetRelid(viewrel, false); ruledef = pg_do_getviewdef(viewoid); PG_RETURN_TEXT_P(ruledef); } /* * Common code for by-OID and by-name variants of pg_get_viewdef */ static text * pg_do_getviewdef(Oid viewoid) { text *ruledef; Datum args[2]; char nulls[2]; int spirc; HeapTuple ruletup; TupleDesc rulettc; StringInfoData buf; int len; /* * Connect to SPI manager */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "get_viewdef: cannot connect to SPI manager"); /* * 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]; void *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_execp(plan_getviewrule, args, nulls, 2); if (spirc != SPI_OK_SELECT) elog(ERROR, "failed to get pg_rewrite tuple for view %u", viewoid); initStringInfo(&buf); if (SPI_processed != 1) appendStringInfo(&buf, "Not a view"); else { /* * Get the rules definition and put it into executors memory */ ruletup = SPI_tuptable->vals[0]; rulettc = SPI_tuptable->tupdesc; make_viewdef(&buf, ruletup, rulettc); } len = buf.len + VARHDRSZ; ruledef = SPI_palloc(len); VARATT_SIZEP(ruledef) = len; memcpy(VARDATA(ruledef), buf.data, buf.len); pfree(buf.data); /* * Disconnect from SPI manager */ if (SPI_finish() != SPI_OK_FINISH) elog(ERROR, "get_viewdef: SPI_finish() failed"); return ruledef; } /* ---------- * get_indexdef - Get the definition of an index * ---------- */ Datum pg_get_indexdef(PG_FUNCTION_ARGS) { Oid indexrelid = PG_GETARG_OID(0); text *indexdef; HeapTuple ht_idx; HeapTuple ht_idxrel; HeapTuple ht_am; Form_pg_index idxrec; Form_pg_class idxrelrec; Form_pg_am amrec; Oid indrelid; int len; int keyno; Oid keycoltypes[INDEX_MAX_KEYS]; StringInfoData buf; StringInfoData keybuf; 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, "syscache lookup for index %u failed", indexrelid); idxrec = (Form_pg_index) GETSTRUCT(ht_idx); indrelid = idxrec->indrelid; Assert(indexrelid == idxrec->indexrelid); /* * Fetch the pg_class tuple of the index relation */ ht_idxrel = SearchSysCache(RELOID, ObjectIdGetDatum(indexrelid), 0, 0, 0); if (!HeapTupleIsValid(ht_idxrel)) elog(ERROR, "syscache lookup for relid %u failed", 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, "syscache lookup for AM %u failed", idxrelrec->relam); amrec = (Form_pg_am) GETSTRUCT(ht_am); /* * 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); appendStringInfo(&buf, "CREATE %sINDEX %s ON %s USING %s (", idxrec->indisunique ? "UNIQUE " : "", quote_identifier(NameStr(idxrelrec->relname)), generate_relation_name(indrelid), quote_identifier(NameStr(amrec->amname))); /* * Collect the indexed attributes in keybuf */ initStringInfo(&keybuf); sep = ""; for (keyno = 0; keyno < INDEX_MAX_KEYS; keyno++) { AttrNumber attnum = idxrec->indkey[keyno]; char *attname; if (attnum == InvalidAttrNumber) break; attname = get_relid_attribute_name(indrelid, attnum); keycoltypes[keyno] = get_atttype(indrelid, attnum); appendStringInfo(&keybuf, sep); sep = ", "; /* * Add the indexed field name */ appendStringInfo(&keybuf, "%s", quote_identifier(attname)); /* * If not a functional index, add the operator class name */ if (idxrec->indproc == InvalidOid) get_opclass_name(idxrec->indclass[keyno], keycoltypes[keyno], &keybuf); } if (idxrec->indproc != InvalidOid) { /* * For functional index say 'func (attrs) opclass' */ appendStringInfo(&buf, "%s(%s)", generate_function_name(idxrec->indproc, keyno, keycoltypes), keybuf.data); get_opclass_name(idxrec->indclass[0], get_func_rettype(idxrec->indproc), &buf); } else { /* * Otherwise say 'attr opclass [, ...]' */ appendStringInfo(&buf, "%s", keybuf.data); } appendStringInfoChar(&buf, ')'); /* * If it's a partial index, decompile and append the predicate */ if (VARSIZE(&idxrec->indpred) > VARHDRSZ) { Node *node; List *context; char *exprstr; char *str; /* Convert TEXT object to C string */ exprstr = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(&idxrec->indpred))); /* Convert expression to node tree */ node = (Node *) stringToNode(exprstr); /* * If top level is a List, assume it is an implicit-AND structure, * and convert to explicit AND. This is needed for partial index * predicates. */ if (node && IsA(node, List)) node = (Node *) make_ands_explicit((List *) node); /* Deparse */ context = deparse_context_for(get_rel_name(indrelid), indrelid); str = deparse_expression(node, context, false); appendStringInfo(&buf, " WHERE %s", str); } /* * Create the result as a TEXT datum, and free working data */ len = buf.len + VARHDRSZ; indexdef = (text *) palloc(len); VARATT_SIZEP(indexdef) = len; memcpy(VARDATA(indexdef), buf.data, buf.len); pfree(buf.data); pfree(keybuf.data); ReleaseSysCache(ht_idx); ReleaseSysCache(ht_idxrel); ReleaseSysCache(ht_am); PG_RETURN_TEXT_P(indexdef); } /* * pg_get_constraintdef * * Returns the definition for the constraint, ie, everything that needs to * appear after "ALTER TABLE ... ADD CONSTRAINT ". * * XXX The present implementation only works for foreign-key constraints, but * it could and should handle anything pg_constraint stores. */ Datum pg_get_constraintdef(PG_FUNCTION_ARGS) { Oid constraintId = PG_GETARG_OID(0); text *result; StringInfoData buf; int len; Relation conDesc; SysScanDesc conscan; ScanKeyData skey[1]; HeapTuple tup; Form_pg_constraint conForm; /* * Fetch the pg_constraint row. There's no syscache for pg_constraint * so we must do it the hard way. */ conDesc = heap_openr(ConstraintRelationName, AccessShareLock); ScanKeyEntryInitialize(&skey[0], 0x0, ObjectIdAttributeNumber, F_OIDEQ, ObjectIdGetDatum(constraintId)); conscan = systable_beginscan(conDesc, ConstraintOidIndex, true, SnapshotNow, 1, skey); tup = systable_getnext(conscan); if (!HeapTupleIsValid(tup)) elog(ERROR, "Failed to find constraint with OID %u", constraintId); conForm = (Form_pg_constraint) GETSTRUCT(tup); initStringInfo(&buf); 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 = heap_getattr(tup, Anum_pg_constraint_conkey, RelationGetDescr(conDesc), &isnull); if (isnull) elog(ERROR, "pg_get_constraintdef: 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)); /* Fetch and build referenced-column list */ val = heap_getattr(tup, Anum_pg_constraint_confkey, RelationGetDescr(conDesc), &isnull); if (isnull) elog(ERROR, "pg_get_constraintdef: 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, "pg_get_constraintdef: Unknown confmatchtype '%c' for constraint %u", conForm->confmatchtype, constraintId); string = ""; /* keep compiler quiet */ break; } appendStringInfo(&buf, "%s", string); /* Add ON UPDATE and ON DELETE clauses */ switch (conForm->confupdtype) { case FKCONSTR_ACTION_NOACTION: string = "NO ACTION"; 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, "pg_get_constraintdef: Unknown confupdtype '%c' for constraint %u", conForm->confupdtype, constraintId); string = ""; /* keep compiler quiet */ break; } appendStringInfo(&buf, " ON UPDATE %s", string); switch (conForm->confdeltype) { case FKCONSTR_ACTION_NOACTION: string = "NO ACTION"; 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, "pg_get_constraintdef: Unknown confdeltype '%c' for constraint %u", conForm->confdeltype, constraintId); string = ""; /* keep compiler quiet */ break; } appendStringInfo(&buf, " ON DELETE %s", string); break; } /* * XXX Add more code here for other contypes */ default: elog(ERROR, "pg_get_constraintdef: unsupported constraint type '%c'", conForm->contype); break; } /* Record the results */ len = buf.len + VARHDRSZ; result = (text *) palloc(len); VARATT_SIZEP(result) = len; memcpy(VARDATA(result), buf.data, buf.len); /* Cleanup */ pfree(buf.data); systable_endscan(conscan); heap_close(conDesc, AccessShareLock); PG_RETURN_TEXT_P(result); } /* * 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), true, 2, 's', &keys, &nKeys); for (j = 0; j < nKeys; j++) { char *colName; colName = get_attname(relId, DatumGetInt16(keys[j])); if (j == 0) appendStringInfo(buf, "%s", 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. * ---------- */ Datum pg_get_expr(PG_FUNCTION_ARGS) { text *expr = PG_GETARG_TEXT_P(0); Oid relid = PG_GETARG_OID(1); text *result; Node *node; List *context; char *exprstr; char *relname; char *str; /* Get the name for the relation */ relname = get_rel_name(relid); if (relname == NULL) PG_RETURN_NULL(); /* should we raise an error? */ /* Convert input TEXT object to C string */ exprstr = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(expr))); /* Convert expression to node tree */ node = (Node *) stringToNode(exprstr); /* * If top level is a List, assume it is an implicit-AND structure, and * convert to explicit AND. This is needed for partial index * predicates. */ if (node && IsA(node, List)) node = (Node *) make_ands_explicit((List *) node); /* Deparse */ context = deparse_context_for(relname, relid); str = deparse_expression(node, context, false); /* Pass the result back as TEXT */ result = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(str))); PG_RETURN_TEXT_P(result); } /* ---------- * get_userbyid - Get a user name by usesysid and * fallback to 'unknown (UID=n)' * ---------- */ Datum pg_get_userbyid(PG_FUNCTION_ARGS) { int32 uid = PG_GETARG_INT32(0); Name result; HeapTuple usertup; Form_pg_shadow user_rec; /* * Allocate space for the result */ result = (Name) palloc(NAMEDATALEN); memset(NameStr(*result), 0, NAMEDATALEN); /* * Get the pg_shadow entry and print the result */ usertup = SearchSysCache(SHADOWSYSID, ObjectIdGetDatum(uid), 0, 0, 0); if (HeapTupleIsValid(usertup)) { user_rec = (Form_pg_shadow) GETSTRUCT(usertup); StrNCpy(NameStr(*result), NameStr(user_rec->usename), NAMEDATALEN); ReleaseSysCache(usertup); } else sprintf(NameStr(*result), "unknown (UID=%d)", uid); PG_RETURN_NAME(result); } /* ---------- * deparse_expression - 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. * * The result is a palloc'd string. * ---------- */ char * deparse_expression(Node *expr, List *dpcontext, bool forceprefix) { StringInfoData buf; deparse_context context; initStringInfo(&buf); context.buf = &buf; context.namespaces = dpcontext; context.varprefix = forceprefix; get_rule_expr(expr, &context); 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 = makeList1(rte); dpns->outer_varno = dpns->inner_varno = 0; dpns->outer_rte = dpns->inner_rte = NULL; /* Return a one-deep namespace stack */ return makeList1(dpns); } /* * deparse_context_for_plan - Build deparse context for a plan node * * We assume we are dealing with an upper-level plan node having either * one or two referenceable children (pass innercontext = NULL if only one). * The passed-in Nodes should be made using deparse_context_for_subplan * and/or deparse_context_for_relation. The resulting context will work * for deparsing quals, tlists, etc of the plan node. * * An rtable list can also be passed in case plain Vars might be seen. * This is not needed for true upper-level expressions, but is helpful for * Sort nodes and similar cases with slightly bogus targetlists. */ List * deparse_context_for_plan(int outer_varno, Node *outercontext, int inner_varno, Node *innercontext, List *rtable) { deparse_namespace *dpns; dpns = (deparse_namespace *) palloc(sizeof(deparse_namespace)); dpns->rtable = rtable; dpns->outer_varno = outer_varno; dpns->outer_rte = (RangeTblEntry *) outercontext; dpns->inner_varno = inner_varno; dpns->inner_rte = (RangeTblEntry *) innercontext; /* Return a one-deep namespace stack */ return makeList1(dpns); } /* * deparse_context_for_rte - Build deparse context for 1 relation * * Helper routine to build one of the inputs for deparse_context_for_plan. * * The returned node is actually the given RangeTblEntry, but we declare it * as just Node to discourage callers from assuming anything. */ Node * deparse_context_for_rte(RangeTblEntry *rte) { return (Node *) rte; } /* * deparse_context_for_subplan - Build deparse context for a plan node * * Helper routine to build one of the inputs for deparse_context_for_plan. * Pass the tlist of the subplan node, plus the query rangetable. * * The returned node is actually a RangeTblEntry, but we declare it as just * Node to discourage callers from assuming anything. */ Node * deparse_context_for_subplan(const char *name, List *tlist, List *rtable) { RangeTblEntry *rte = makeNode(RangeTblEntry); List *attrs = NIL; int nattrs = 0; int rtablelength = length(rtable); List *tl; char buf[32]; foreach(tl, tlist) { TargetEntry *tle = lfirst(tl); Resdom *resdom = tle->resdom; nattrs++; Assert(resdom->resno == nattrs); if (resdom->resname) { attrs = lappend(attrs, makeString(resdom->resname)); continue; } if (tle->expr && IsA(tle->expr, Var)) { Var *var = (Var *) tle->expr; /* varno/varattno won't be any good, but varnoold might be */ if (var->varnoold > 0 && var->varnoold <= rtablelength) { RangeTblEntry *varrte = rt_fetch(var->varnoold, rtable); char *varname; varname = get_rte_attribute_name(varrte, var->varoattno); attrs = lappend(attrs, makeString(varname)); continue; } } /* Fallback if can't get name */ snprintf(buf, sizeof(buf), "?column%d?", resdom->resno); attrs = lappend(attrs, makeString(pstrdup(buf))); } rte->rtekind = RTE_SPECIAL; /* XXX */ rte->relid = InvalidOid; rte->eref = makeAlias(name, attrs); rte->inh = false; rte->inFromCl = true; return (Node *) rte; } /* ---------- * make_ruledef - reconstruct the CREATE RULE command * for a given pg_rewrite tuple * ---------- */ static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc) { 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 ON ", quote_identifier(rulename)); /* 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: elog(ERROR, "get_ruledef: 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)); 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; 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 *) lfirst(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); context.buf = buf; context.namespaces = makeList1(&dpns); context.varprefix = (length(query->rtable) != 1); dpns.rtable = query->rtable; dpns.outer_varno = dpns.inner_varno = 0; dpns.outer_rte = dpns.inner_rte = NULL; get_rule_expr(qual, &context); } appendStringInfo(buf, " DO "); /* The INSTEAD keyword (if so) */ if (is_instead) appendStringInfo(buf, "INSTEAD "); /* Finally the rules actions */ if (length(actions) > 1) { List *action; Query *query; appendStringInfo(buf, "("); foreach(action, actions) { query = (Query *) lfirst(action); get_query_def(query, buf, NIL, NULL); appendStringInfo(buf, "; "); } appendStringInfo(buf, ");"); } else if (length(actions) == 0) { appendStringInfo(buf, "NOTHING;"); } else { Query *query; query = (Query *) lfirst(actions); get_query_def(query, buf, NIL, NULL); appendStringInfo(buf, ";"); } } /* ---------- * make_viewdef - reconstruct the SELECT part of a * view rewrite rule * ---------- */ static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc) { 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 (length(actions) != 1) { appendStringInfo(buf, "Not a view"); return; } query = (Query *) lfirst(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)); 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) { deparse_context context; deparse_namespace dpns; context.buf = buf; context.namespaces = lcons(&dpns, parentnamespace); context.varprefix = (parentnamespace != NIL || length(query->rtable) != 1); dpns.rtable = query->rtable; dpns.outer_varno = dpns.inner_varno = 0; dpns.outer_rte = dpns.inner_rte = 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, "get_query_def: unknown query command type %d", query->commandType); break; } } /* ---------- * 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; bool force_colno; char *sep; List *l; /* * If the Query node has a setOperations tree, then it's the top level * of a UNION/INTERSECT/EXCEPT query; only the 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) { appendStringInfo(buf, " ORDER BY "); sep = ""; foreach(l, query->sortClause) { SortClause *srt = (SortClause *) lfirst(l); Node *sortexpr; Oid sortcoltype; char *opname; appendStringInfo(buf, sep); sortexpr = get_rule_sortgroupclause(srt, query->targetList, force_colno, context); sortcoltype = exprType(sortexpr); opname = generate_operator_name(srt->sortop, sortcoltype, sortcoltype); if (strcmp(opname, "<") != 0) { if (strcmp(opname, ">") == 0) appendStringInfo(buf, " DESC"); else appendStringInfo(buf, " USING %s", opname); } sep = ", "; } } /* Add the LIMIT clause if given */ if (query->limitOffset != NULL) { appendStringInfo(buf, " OFFSET "); get_rule_expr(query->limitOffset, context); } if (query->limitCount != NULL) { appendStringInfo(buf, " LIMIT "); if (IsA(query->limitCount, Const) && ((Const *) query->limitCount)->constisnull) appendStringInfo(buf, "ALL"); else get_rule_expr(query->limitCount, context); } } static void get_basic_select_query(Query *query, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; char *sep; List *l; int colno; /* * Build up the query string - first we say SELECT */ appendStringInfo(buf, "SELECT"); /* Add the DISTINCT clause if given */ if (query->distinctClause != NIL) { if (has_distinct_on_clause(query)) { appendStringInfo(buf, " DISTINCT ON ("); sep = ""; foreach(l, query->distinctClause) { SortClause *srt = (SortClause *) lfirst(l); appendStringInfo(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) */ sep = " "; colno = 0; foreach(l, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); bool tell_as = false; char *colname; if (tle->resdom->resjunk) continue; /* ignore junk entries */ appendStringInfo(buf, sep); sep = ", "; colno++; /* Do NOT use get_tle_expr here; see its comments! */ get_rule_expr(tle->expr, context); /* * 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->resdom->resname; /* Check if we must say AS ... */ if (!IsA(tle->expr, Var)) tell_as = (strcmp(colname, "?column?") != 0); else { Var *var = (Var *) (tle->expr); char *schemaname; char *refname; char *attname; get_names_for_var(var, context, &schemaname, &refname, &attname); tell_as = (attname == NULL || strcmp(attname, colname) != 0); } /* and do if so */ if (tell_as) appendStringInfo(buf, " AS %s", quote_identifier(colname)); } /* Add the FROM clause if needed */ get_from_clause(query, context); /* Add the WHERE clause if given */ if (query->jointree->quals != NULL) { appendStringInfo(buf, " WHERE "); get_rule_expr(query->jointree->quals, context); } /* Add the GROUP BY clause if given */ if (query->groupClause != NULL) { appendStringInfo(buf, " GROUP BY "); sep = ""; foreach(l, query->groupClause) { GroupClause *grp = (GroupClause *) lfirst(l); appendStringInfo(buf, sep); get_rule_sortgroupclause(grp, query->targetList, false, context); sep = ", "; } } /* Add the HAVING clause if given */ if (query->havingQual != NULL) { appendStringInfo(buf, " HAVING "); get_rule_expr(query->havingQual, context); } } static void get_setop_query(Node *setOp, Query *query, deparse_context *context, TupleDesc resultDesc) { StringInfo buf = context->buf; if (IsA(setOp, RangeTblRef)) { RangeTblRef *rtr = (RangeTblRef *) setOp; RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable); Query *subquery = rte->subquery; Assert(subquery != NULL); get_query_def(subquery, buf, context->namespaces, resultDesc); } else if (IsA(setOp, SetOperationStmt)) { SetOperationStmt *op = (SetOperationStmt *) setOp; appendStringInfo(buf, "(("); get_setop_query(op->larg, query, context, resultDesc); switch (op->op) { case SETOP_UNION: appendStringInfo(buf, ") UNION "); break; case SETOP_INTERSECT: appendStringInfo(buf, ") INTERSECT "); break; case SETOP_EXCEPT: appendStringInfo(buf, ") EXCEPT "); break; default: elog(ERROR, "get_setop_query: unexpected set op %d", (int) op->op); } if (op->all) appendStringInfo(buf, "ALL ("); else appendStringInfo(buf, "("); get_setop_query(op->rarg, query, context, resultDesc); appendStringInfo(buf, "))"); } else { elog(ERROR, "get_setop_query: unexpected node %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(SortClause *srt, List *tlist, bool force_colno, deparse_context *context) { StringInfo buf = context->buf; TargetEntry *tle; Node *expr; tle = get_sortgroupclause_tle(srt, tlist); expr = tle->expr; /* * Use column-number form if requested by caller or if expression is a * constant --- a constant is ambiguous (and will be misinterpreted by * findTargetlistEntry()) if we dump it explicitly. */ if (force_colno || (expr && IsA(expr, Const))) { Assert(!tle->resdom->resjunk); appendStringInfo(buf, "%d", tle->resdom->resno); } else get_rule_expr(expr, context); return expr; } /* ---------- * 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 *rte; char *sep; List *l; /* * If it's an INSERT ... SELECT there will be a single subquery RTE * for the SELECT. */ foreach(l, query->rtable) { rte = (RangeTblEntry *) lfirst(l); if (rte->rtekind != RTE_SUBQUERY) continue; if (select_rte) elog(ERROR, "get_insert_query_def: too many RTEs in INSERT!"); select_rte = rte; } /* * Start the query with INSERT INTO relname */ rte = rt_fetch(query->resultRelation, query->rtable); Assert(rte->rtekind == RTE_RELATION); appendStringInfo(buf, "INSERT INTO %s", generate_relation_name(rte->relid)); /* Add the insert-column-names list */ sep = " ("; foreach(l, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resdom->resjunk) continue; /* ignore junk entries */ appendStringInfo(buf, sep); sep = ", "; appendStringInfo(buf, "%s", quote_identifier(tle->resdom->resname)); } appendStringInfo(buf, ") "); /* Add the VALUES or the SELECT */ if (select_rte == NULL) { appendStringInfo(buf, "VALUES ("); sep = ""; foreach(l, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resdom->resjunk) continue; /* ignore junk entries */ appendStringInfo(buf, sep); sep = ", "; get_tle_expr(tle, context); } appendStringInfoChar(buf, ')'); } else get_query_def(select_rte->subquery, buf, NIL, 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; List *l; /* * Start the query with UPDATE relname SET */ rte = rt_fetch(query->resultRelation, query->rtable); Assert(rte->rtekind == RTE_RELATION); appendStringInfo(buf, "UPDATE %s%s SET ", only_marker(rte), generate_relation_name(rte->relid)); /* Add the comma separated list of 'attname = value' */ sep = ""; foreach(l, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resdom->resjunk) continue; /* ignore junk entries */ appendStringInfo(buf, sep); sep = ", "; /* * If the update expression is an array assignment, we mustn't put * out "attname =" here; it will come out of the display of the * ArrayRef node instead. */ if (!tleIsArrayAssign(tle)) appendStringInfo(buf, "%s = ", quote_identifier(tle->resdom->resname)); get_tle_expr(tle, context); } /* Add the FROM clause if needed */ get_from_clause(query, context); /* Finally add a WHERE clause if given */ if (query->jointree->quals != NULL) { appendStringInfo(buf, " WHERE "); get_rule_expr(query->jointree->quals, context); } } /* ---------- * 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); appendStringInfo(buf, "DELETE FROM %s%s", only_marker(rte), generate_relation_name(rte->relid)); /* Add a WHERE clause if given */ if (query->jointree->quals != NULL) { appendStringInfo(buf, " WHERE "); get_rule_expr(query->jointree->quals, context); } } /* ---------- * 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; appendStringInfo(buf, "NOTIFY %s", quote_qualified_identifier(stmt->relation->schemaname, stmt->relation->relname)); } else elog(ERROR, "get_utility_query_def: unexpected statement type"); } /* * Get the schemaname, refname and attname for a (possibly nonlocal) Var. * * schemaname is usually returned as NULL. It will be non-null only if * use of the unqualified refname would find the wrong RTE. * * refname will be returned as NULL if the Var references an unnamed join. * In this case the Var *must* be displayed without any qualification. * * attname will be returned as NULL if the Var represents a whole tuple * of the relation. (Typically we'd want to display the Var as "foo.*", * but it's convenient to return NULL to make it easier for callers to * distinguish this case.) */ static void get_names_for_var(Var *var, deparse_context *context, char **schemaname, char **refname, char **attname) { List *nslist = context->namespaces; int sup = var->varlevelsup; deparse_namespace *dpns; RangeTblEntry *rte; /* Find appropriate nesting depth */ while (sup-- > 0 && nslist != NIL) nslist = lnext(nslist); if (nslist == NIL) elog(ERROR, "get_names_for_var: bogus varlevelsup %d", var->varlevelsup); dpns = (deparse_namespace *) lfirst(nslist); /* Find the relevant RTE */ if (var->varno >= 1 && var->varno <= length(dpns->rtable)) rte = rt_fetch(var->varno, dpns->rtable); else if (var->varno == dpns->outer_varno) rte = dpns->outer_rte; else if (var->varno == dpns->inner_varno) rte = dpns->inner_rte; else rte = NULL; if (rte == NULL) elog(ERROR, "get_names_for_var: bogus varno %d", var->varno); /* Emit results */ *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) { /* Unnamed join has neither schemaname nor refname */ *refname = NULL; } } if (var->varattno == InvalidAttrNumber) *attname = NULL; else *attname = get_rte_attribute_name(rte, var->varattno); } /* * 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; List *nslist; foreach(nslist, context->namespaces) { deparse_namespace *dpns = (deparse_namespace *) lfirst(nslist); List *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 (dpns->outer_rte && strcmp(dpns->outer_rte->eref->aliasname, refname) == 0) { if (result) return NULL; /* it's ambiguous */ result = dpns->outer_rte; } if (dpns->inner_rte && strcmp(dpns->inner_rte->eref->aliasname, refname) == 0) { if (result) return NULL; /* it's ambiguous */ result = dpns->inner_rte; } if (result) break; } return result; } /* ---------- * get_rule_expr - Parse back an expression * ---------- */ static void get_rule_expr(Node *node, deparse_context *context) { 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. * * There might be some work left here to support additional node types. * Can we ever see Param nodes here? */ switch (nodeTag(node)) { case T_Const: get_const_expr((Const *) node, context); break; case T_Var: { Var *var = (Var *) node; char *schemaname; char *refname; char *attname; get_names_for_var(var, context, &schemaname, &refname, &attname); if (refname && (context->varprefix || attname == NULL)) { if (schemaname) appendStringInfo(buf, "%s.", quote_identifier(schemaname)); if (strcmp(refname, "*NEW*") == 0) appendStringInfo(buf, "new."); else if (strcmp(refname, "*OLD*") == 0) appendStringInfo(buf, "old."); else appendStringInfo(buf, "%s.", quote_identifier(refname)); } if (attname) appendStringInfo(buf, "%s", quote_identifier(attname)); else appendStringInfo(buf, "*"); } break; case T_Expr: { Expr *expr = (Expr *) node; List *args = expr->args; /* * Expr nodes have to be handled a bit detailed */ switch (expr->opType) { case OP_EXPR: get_oper_expr(expr, context); break; case DISTINCT_EXPR: appendStringInfoChar(buf, '('); Assert(length(args) == 2); { /* binary operator */ Node *arg1 = (Node *) lfirst(args); Node *arg2 = (Node *) lsecond(args); get_rule_expr(arg1, context); appendStringInfo(buf, " IS DISTINCT FROM "); get_rule_expr(arg2, context); } appendStringInfoChar(buf, ')'); break; case FUNC_EXPR: get_func_expr(expr, context); break; case OR_EXPR: appendStringInfoChar(buf, '('); get_rule_expr((Node *) lfirst(args), context); while ((args = lnext(args)) != NIL) { appendStringInfo(buf, " OR "); get_rule_expr((Node *) lfirst(args), context); } appendStringInfoChar(buf, ')'); break; case AND_EXPR: appendStringInfoChar(buf, '('); get_rule_expr((Node *) lfirst(args), context); while ((args = lnext(args)) != NIL) { appendStringInfo(buf, " AND "); get_rule_expr((Node *) lfirst(args), context); } appendStringInfoChar(buf, ')'); break; case NOT_EXPR: appendStringInfo(buf, "(NOT "); get_rule_expr((Node *) lfirst(args), context); appendStringInfoChar(buf, ')'); break; case SUBPLAN_EXPR: /* * We cannot see an already-planned subplan in rule * deparsing, only while EXPLAINing a query plan. * For now, just punt. */ appendStringInfo(buf, "(subplan)"); break; default: elog(ERROR, "get_rule_expr: expr opType %d not supported", expr->opType); } } break; case T_Aggref: get_agg_expr((Aggref *) node, context); break; case T_ArrayRef: { ArrayRef *aref = (ArrayRef *) node; bool savevarprefix = context->varprefix; List *lowlist; List *uplist; /* * If we are doing UPDATE array[n] = expr, we need to * suppress any prefix on the array name. Currently, that * is the only context in which we will see a non-null * refassgnexpr --- but someday a smarter test may be * needed. */ if (aref->refassgnexpr) context->varprefix = false; get_rule_expr(aref->refexpr, context); context->varprefix = savevarprefix; lowlist = aref->reflowerindexpr; foreach(uplist, aref->refupperindexpr) { appendStringInfo(buf, "["); if (lowlist) { get_rule_expr((Node *) lfirst(lowlist), context); appendStringInfo(buf, ":"); lowlist = lnext(lowlist); } get_rule_expr((Node *) lfirst(uplist), context); appendStringInfo(buf, "]"); } if (aref->refassgnexpr) { appendStringInfo(buf, " = "); get_rule_expr(aref->refassgnexpr, context); } } break; case T_FieldSelect: { FieldSelect *fselect = (FieldSelect *) node; Oid argType = exprType(fselect->arg); HeapTuple typetup; Form_pg_type typeStruct; Oid typrelid; char *fieldname; /* lookup arg type and get the field name */ typetup = SearchSysCache(TYPEOID, ObjectIdGetDatum(argType), 0, 0, 0); if (!HeapTupleIsValid(typetup)) elog(ERROR, "cache lookup of type %u failed", argType); typeStruct = (Form_pg_type) GETSTRUCT(typetup); typrelid = typeStruct->typrelid; if (!OidIsValid(typrelid)) elog(ERROR, "Argument type %s of FieldSelect is not a tuple type", format_type_be(argType)); ReleaseSysCache(typetup); fieldname = get_relid_attribute_name(typrelid, fselect->fieldnum); /* * If the argument is simple enough, we could emit * arg.fieldname, but most cases where FieldSelect is used * are *not* simple. So, always use parenthesized syntax. */ appendStringInfoChar(buf, '('); get_rule_expr(fselect->arg, context); appendStringInfo(buf, ").%s", quote_identifier(fieldname)); } break; case T_RelabelType: { RelabelType *relabel = (RelabelType *) node; appendStringInfoChar(buf, '('); get_rule_expr(relabel->arg, context); appendStringInfo(buf, ")::%s", format_type_with_typemod(relabel->resulttype, relabel->resulttypmod)); } break; case T_CaseExpr: { CaseExpr *caseexpr = (CaseExpr *) node; List *temp; appendStringInfo(buf, "CASE"); foreach(temp, caseexpr->args) { CaseWhen *when = (CaseWhen *) lfirst(temp); appendStringInfo(buf, " WHEN "); get_rule_expr(when->expr, context); appendStringInfo(buf, " THEN "); get_rule_expr(when->result, context); } appendStringInfo(buf, " ELSE "); get_rule_expr(caseexpr->defresult, context); appendStringInfo(buf, " END"); } break; case T_NullTest: { NullTest *ntest = (NullTest *) node; appendStringInfo(buf, "("); get_rule_expr(ntest->arg, context); switch (ntest->nulltesttype) { case IS_NULL: appendStringInfo(buf, " IS NULL)"); break; case IS_NOT_NULL: appendStringInfo(buf, " IS NOT NULL)"); break; default: elog(ERROR, "get_rule_expr: unexpected nulltesttype %d", (int) ntest->nulltesttype); } } break; case T_BooleanTest: { BooleanTest *btest = (BooleanTest *) node; appendStringInfo(buf, "("); get_rule_expr(btest->arg, context); 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, "get_rule_expr: unexpected booltesttype %d", (int) btest->booltesttype); } } break; case T_SubLink: get_sublink_expr(node, context); break; case T_Param: { Param *param = (Param *) node; switch (param->paramkind) { case PARAM_NAMED: case PARAM_NEW: case PARAM_OLD: appendStringInfo(buf, "$%s", param->paramname); break; case PARAM_NUM: case PARAM_EXEC: appendStringInfo(buf, "$%d", param->paramid); break; default: appendStringInfo(buf, "(param)"); break; } } break; default: elog(ERROR, "get_rule_expr: unknown node type %d", nodeTag(node)); break; } } /* * get_oper_expr - Parse back an Oper node */ static void get_oper_expr(Expr *expr, deparse_context *context) { StringInfo buf = context->buf; Oid opno = ((Oper *) expr->oper)->opno; List *args = expr->args; appendStringInfoChar(buf, '('); if (length(args) == 2) { /* binary operator */ Node *arg1 = (Node *) lfirst(args); Node *arg2 = (Node *) lsecond(args); get_rule_expr(arg1, context); appendStringInfo(buf, " %s ", generate_operator_name(opno, exprType(arg1), exprType(arg2))); get_rule_expr(arg2, context); } else { /* unary operator --- but which side? */ Node *arg = (Node *) lfirst(args); HeapTuple tp; Form_pg_operator optup; tp = SearchSysCache(OPEROID, ObjectIdGetDatum(opno), 0, 0, 0); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup for operator %u failed", 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(arg, context); break; case 'r': get_rule_expr(arg, context); appendStringInfo(buf, " %s", generate_operator_name(opno, exprType(arg), InvalidOid)); break; default: elog(ERROR, "get_rule_expr: bogus oprkind"); } ReleaseSysCache(tp); } appendStringInfoChar(buf, ')'); } /* * get_func_expr - Parse back a Func node */ static void get_func_expr(Expr *expr, deparse_context *context) { StringInfo buf = context->buf; Func *func = (Func *) (expr->oper); Oid funcoid = func->funcid; int32 coercedTypmod; Oid argtypes[FUNC_MAX_ARGS]; int nargs; List *l; char *sep; /* * Check to see if function is a length-coercion function for some * datatype. If so, display the operation as a type cast. */ if (exprIsLengthCoercion((Node *) expr, &coercedTypmod)) { Node *arg = lfirst(expr->args); Oid rettype = get_func_rettype(funcoid); char *typdesc; /* * Strip off any type coercions on the input, so we don't print * redundancies like x::bpchar::character(8). * * XXX Are there any cases where this is a bad idea? */ arg = strip_type_coercion(arg, rettype); appendStringInfoChar(buf, '('); get_rule_expr(arg, context); /* * Show typename with appropriate length decoration. Note that * since exprIsLengthCoercion succeeded, the function's output * type is the right thing to report. Also note we don't need * to quote the result of format_type_with_typemod: it takes * care of double-quoting any identifier that needs it. */ typdesc = format_type_with_typemod(rettype, coercedTypmod); appendStringInfo(buf, ")::%s", typdesc); pfree(typdesc); return; } /* * Normal function: display as proname(args). First we need to extract * the argument datatypes. */ nargs = 0; foreach(l, expr->args) { Assert(nargs < FUNC_MAX_ARGS); argtypes[nargs] = exprType((Node *) lfirst(l)); nargs++; } appendStringInfo(buf, "%s(", generate_function_name(funcoid, nargs, argtypes)); sep = ""; foreach(l, expr->args) { appendStringInfo(buf, sep); sep = ", "; get_rule_expr((Node *) lfirst(l), context); } 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 argtype = exprType(aggref->target); appendStringInfo(buf, "%s(%s", generate_function_name(aggref->aggfnoid, 1, &argtype), aggref->aggdistinct ? "DISTINCT " : ""); if (aggref->aggstar) appendStringInfo(buf, "*"); else get_rule_expr(aggref->target, context); appendStringInfoChar(buf, ')'); } /* * strip_type_coercion * Strip any type coercions at the top of the given expression tree, * as long as they are coercions to the given datatype. * * A RelabelType node is always a type coercion. A function call is * also considered a type coercion if it has one argument and there is * a cast declared that uses it. * * XXX It'd be better if the parsetree retained some explicit indication * of the coercion, so we didn't need these heuristics. */ static Node * strip_type_coercion(Node *expr, Oid resultType) { if (expr == NULL || exprType(expr) != resultType) return expr; if (IsA(expr, RelabelType)) return strip_type_coercion(((RelabelType *) expr)->arg, resultType); if (IsA(expr, Expr) && ((Expr *) expr)->opType == FUNC_EXPR) { Func *func; HeapTuple procTuple; HeapTuple castTuple; Form_pg_proc procStruct; Form_pg_cast castStruct; func = (Func *) (((Expr *) expr)->oper); Assert(IsA(func, Func)); if (length(((Expr *) expr)->args) != 1) return expr; /* Lookup the function in pg_proc */ procTuple = SearchSysCache(PROCOID, ObjectIdGetDatum(func->funcid), 0, 0, 0); if (!HeapTupleIsValid(procTuple)) elog(ERROR, "cache lookup for proc %u failed", func->funcid); procStruct = (Form_pg_proc) GETSTRUCT(procTuple); /* Double-check func has one arg and correct result type */ if (procStruct->pronargs != 1 || procStruct->prorettype != resultType) { ReleaseSysCache(procTuple); return expr; } /* See if function has is actually declared as a cast */ castTuple = SearchSysCache(CASTSOURCETARGET, ObjectIdGetDatum(procStruct->proargtypes[0]), ObjectIdGetDatum(procStruct->prorettype), 0, 0); if (!HeapTupleIsValid(castTuple)) { ReleaseSysCache(procTuple); return expr; } /* It must also be an implicit cast. */ castStruct = (Form_pg_cast) GETSTRUCT(castTuple); if (!castStruct->castimplicit) { ReleaseSysCache(procTuple); ReleaseSysCache(castTuple); return expr; } /* Okay, it is indeed a type-coercion function */ ReleaseSysCache(procTuple); ReleaseSysCache(castTuple); return strip_type_coercion(lfirst(((Expr *) expr)->args), resultType); } return expr; } /* ---------- * get_tle_expr * * In an INSERT or UPDATE targetlist item, the parser may have inserted * a length-coercion function call to coerce the value to the right * length for the target column. We want to suppress the output of * that function call, otherwise dump/reload/dump... would blow up the * expression by adding more and more layers of length-coercion calls. * * As of 7.0, this hack is no longer absolutely essential, because the parser * is now smart enough not to add a redundant length coercion function call. * But we still suppress the function call just for neatness of displayed * rules. * * Note that this hack must NOT be applied to SELECT targetlist items; * any length coercion appearing there is something the user actually wrote. * ---------- */ static void get_tle_expr(TargetEntry *tle, deparse_context *context) { Expr *expr = (Expr *) (tle->expr); int32 coercedTypmod; /* * If top level is a length coercion to the correct length, suppress * it; else dump the expression normally. */ if (tle->resdom->restypmod >= 0 && exprIsLengthCoercion((Node *) expr, &coercedTypmod) && coercedTypmod == tle->resdom->restypmod) get_rule_expr((Node *) lfirst(expr->args), context); else get_rule_expr(tle->expr, context); } /* ---------- * get_const_expr * * Make a string representation of a Const * ---------- */ static void get_const_expr(Const *constval, deparse_context *context) { StringInfo buf = context->buf; HeapTuple typetup; Form_pg_type typeStruct; char *extval; char *valptr; if (constval->constisnull) { /* * Always label the type of a NULL constant to prevent misdecisions * about type when reparsing. */ appendStringInfo(buf, "NULL::%s", format_type_with_typemod(constval->consttype, -1)); return; } typetup = SearchSysCache(TYPEOID, ObjectIdGetDatum(constval->consttype), 0, 0, 0); if (!HeapTupleIsValid(typetup)) elog(ERROR, "cache lookup of type %u failed", constval->consttype); typeStruct = (Form_pg_type) GETSTRUCT(typetup); extval = DatumGetCString(OidFunctionCall3(typeStruct->typoutput, constval->constvalue, ObjectIdGetDatum(typeStruct->typelem), Int32GetDatum(-1))); switch (constval->consttype) { case INT2OID: case INT4OID: case OIDOID: /* int types */ case FLOAT4OID: case FLOAT8OID: /* float types */ /* These types are printed without quotes */ appendStringInfo(buf, extval); break; default: /* * We must quote any funny characters in the constant's * representation. XXX Any MULTIBYTE considerations here? */ appendStringInfoChar(buf, '\''); for (valptr = extval; *valptr; valptr++) { char ch = *valptr; if (ch == '\'' || ch == '\\') { appendStringInfoChar(buf, '\\'); appendStringInfoChar(buf, ch); } else if (((unsigned char) ch) < ((unsigned char) ' ')) appendStringInfo(buf, "\\%03o", (int) ch); else appendStringInfoChar(buf, ch); } appendStringInfoChar(buf, '\''); break; } pfree(extval); switch (constval->consttype) { case INT4OID: case FLOAT8OID: case UNKNOWNOID: /* These types can be left unlabeled */ break; default: appendStringInfo(buf, "::%s", format_type_with_typemod(constval->consttype, -1)); break; } ReleaseSysCache(typetup); } /* ---------- * get_sublink_expr - Parse back a sublink * ---------- */ static void get_sublink_expr(Node *node, deparse_context *context) { StringInfo buf = context->buf; SubLink *sublink = (SubLink *) node; Query *query = (Query *) (sublink->subselect); List *l; char *sep; Oper *oper; bool need_paren; appendStringInfoChar(buf, '('); if (sublink->lefthand != NIL) { need_paren = (length(sublink->lefthand) > 1); if (need_paren) appendStringInfoChar(buf, '('); sep = ""; foreach(l, sublink->lefthand) { appendStringInfo(buf, sep); sep = ", "; get_rule_expr((Node *) lfirst(l), context); } if (need_paren) appendStringInfo(buf, ") "); else appendStringInfoChar(buf, ' '); } need_paren = true; /* * XXX we assume here that we can get away without qualifying the * operator name. Since the name may imply multiple physical operators * it's rather difficult to do otherwise --- in fact, if the operators * are in different namespaces any attempt to qualify would surely fail. */ switch (sublink->subLinkType) { case EXISTS_SUBLINK: appendStringInfo(buf, "EXISTS "); break; case ANY_SUBLINK: oper = (Oper *) lfirst(sublink->oper); appendStringInfo(buf, "%s ANY ", get_opname(oper->opno)); break; case ALL_SUBLINK: oper = (Oper *) lfirst(sublink->oper); appendStringInfo(buf, "%s ALL ", get_opname(oper->opno)); break; case MULTIEXPR_SUBLINK: oper = (Oper *) lfirst(sublink->oper); appendStringInfo(buf, "%s ", get_opname(oper->opno)); break; case EXPR_SUBLINK: need_paren = false; break; default: elog(ERROR, "get_sublink_expr: unsupported sublink type %d", sublink->subLinkType); break; } if (need_paren) appendStringInfoChar(buf, '('); get_query_def(query, buf, context->namespaces, NULL); if (need_paren) appendStringInfo(buf, "))"); else appendStringInfoChar(buf, ')'); } /* ---------- * get_from_clause - Parse back a FROM clause * ---------- */ static void get_from_clause(Query *query, deparse_context *context) { StringInfo buf = context->buf; char *sep; List *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.) Also ignore the rule pseudo-RTEs for NEW * and OLD. */ sep = " FROM "; 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 (strcmp(rte->eref->aliasname, "*NEW*") == 0) continue; if (strcmp(rte->eref->aliasname, "*OLD*") == 0) continue; } appendStringInfo(buf, sep); get_from_clause_item(jtnode, query, context); sep = ", "; } } 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); switch (rte->rtekind) { case RTE_RELATION: /* Normal relation RTE */ appendStringInfo(buf, "%s%s", only_marker(rte), generate_relation_name(rte->relid)); break; case RTE_SUBQUERY: /* Subquery RTE */ appendStringInfoChar(buf, '('); get_query_def(rte->subquery, buf, context->namespaces, NULL); appendStringInfoChar(buf, ')'); break; case RTE_FUNCTION: /* Function RTE */ get_rule_expr(rte->funcexpr, context); break; default: elog(ERROR, "unexpected rte kind %d", (int) rte->rtekind); break; } if (rte->alias != NULL) { appendStringInfo(buf, " %s", quote_identifier(rte->alias->aliasname)); if (rte->alias->colnames != NIL) { List *col; appendStringInfo(buf, "("); foreach(col, rte->alias->colnames) { if (col != rte->alias->colnames) appendStringInfo(buf, ", "); appendStringInfo(buf, "%s", quote_identifier(strVal(lfirst(col)))); } appendStringInfoChar(buf, ')'); } } 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)); } } else if (IsA(jtnode, JoinExpr)) { JoinExpr *j = (JoinExpr *) jtnode; appendStringInfoChar(buf, '('); get_from_clause_item(j->larg, query, context); if (j->isNatural) appendStringInfo(buf, " NATURAL"); switch (j->jointype) { case JOIN_INNER: if (j->quals) appendStringInfo(buf, " JOIN "); else appendStringInfo(buf, " CROSS JOIN "); break; case JOIN_LEFT: appendStringInfo(buf, " LEFT JOIN "); break; case JOIN_FULL: appendStringInfo(buf, " FULL JOIN "); break; case JOIN_RIGHT: appendStringInfo(buf, " RIGHT JOIN "); break; case JOIN_UNION: appendStringInfo(buf, " UNION JOIN "); break; default: elog(ERROR, "get_from_clause_item: unknown join type %d", (int) j->jointype); } get_from_clause_item(j->rarg, query, context); if (!j->isNatural) { if (j->using) { List *col; appendStringInfo(buf, " USING ("); foreach(col, j->using) { if (col != j->using) appendStringInfo(buf, ", "); appendStringInfo(buf, "%s", quote_identifier(strVal(lfirst(col)))); } appendStringInfoChar(buf, ')'); } else if (j->quals) { appendStringInfo(buf, " ON ("); get_rule_expr(j->quals, context); appendStringInfoChar(buf, ')'); } } 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)); if (j->alias->colnames != NIL) { List *col; appendStringInfo(buf, "("); foreach(col, j->alias->colnames) { if (col != j->alias->colnames) appendStringInfo(buf, ", "); appendStringInfo(buf, "%s", quote_identifier(strVal(lfirst(col)))); } appendStringInfoChar(buf, ')'); } } } else elog(ERROR, "get_from_clause_item: unexpected node type %d", nodeTag(jtnode)); } /* * 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; /* Domains use their base type's default opclass */ if (OidIsValid(actual_datatype)) actual_datatype = getBaseType(actual_datatype); 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 (actual_datatype != opcrec->opcintype || !opcrec->opcdefault) { /* 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); } /* * tleIsArrayAssign - check for array assignment */ static bool tleIsArrayAssign(TargetEntry *tle) { ArrayRef *aref; if (tle->expr == NULL || !IsA(tle->expr, ArrayRef)) return false; aref = (ArrayRef *) tle->expr; if (aref->refassgnexpr == NULL) return false; /* * Currently, it should only be possible to see non-null refassgnexpr * if we are indeed looking at an "UPDATE array[n] = expr" situation. * So aref->refexpr ought to match the tle's target. */ if (aref->refexpr == NULL || !IsA(aref->refexpr, Var) || ((Var *) aref->refexpr)->varattno != tle->resdom->resno) elog(WARNING, "tleIsArrayAssign: I'm confused ..."); return true; } /* * quote_identifier - Quote an identifier only if needed * * When quotes are needed, we palloc the required space; slightly * space-wasteful but well worth it for notational simplicity. */ const char * quote_identifier(const char *ident) { /* * Can avoid quoting if ident starts with a lowercase letter or underscore * and contains only lowercase letters, digits, and underscores, *and* is * not any SQL keyword. Otherwise, supply quotes. */ int nquotes = 0; bool safe; const char *ptr; char *result; char *optr; /* * would like to use macros here, but they might yield * unwanted locale-specific results... */ safe = ((ident[0] >= 'a' && ident[0] <= 'z') || ident[0] == '_'); for (ptr = ident; *ptr; ptr++) { char ch = *ptr; if ((ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || (ch == '_')) { /* okay */ } else { safe = false; if (ch == '"') nquotes++; } } if (safe) { /* * Check for keyword. This test is overly strong, since many of * the "keywords" known to the parser are usable as column names, * but the parser doesn't provide any easy way to test for whether * an identifier is safe or not... so be safe not sorry. * * Note: ScanKeywordLookup() does case-insensitive comparison, but * that's fine, since we already know we have all-lower-case. */ if (ScanKeywordLookup(ident) != NULL) 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 namespace.ident, or just ident if namespace * is NULL, quoting each component if necessary. The result is palloc'd. */ char * quote_qualified_identifier(const char *namespace, const char *ident) { StringInfoData buf; initStringInfo(&buf); if (namespace) appendStringInfo(&buf, "%s.", quote_identifier(namespace)); appendStringInfo(&buf, "%s", 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. */ static char * generate_relation_name(Oid relid) { HeapTuple tp; Form_pg_class reltup; char *nspname; char *result; tp = SearchSysCache(RELOID, ObjectIdGetDatum(relid), 0, 0, 0); if (!HeapTupleIsValid(tp)) elog(ERROR, "cache lookup of relation %u failed", relid); reltup = (Form_pg_class) GETSTRUCT(tp); /* Qualify the name if not visible in search path */ if (RelationIsVisible(relid)) nspname = NULL; else nspname = get_namespace_name(reltup->relnamespace); result = quote_qualified_identifier(nspname, NameStr(reltup->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 types. * (Arg types matter because of ambiguous-function resolution rules.) * * The result includes all necessary quoting and schema-prefixing. */ static char * generate_function_name(Oid funcid, int nargs, Oid *argtypes) { HeapTuple proctup; Form_pg_proc procform; char *proname; char *nspname; char *result; FuncDetailCode p_result; Oid p_funcid; Oid p_rettype; bool p_retset; Oid *p_true_typeids; proctup = SearchSysCache(PROCOID, ObjectIdGetDatum(funcid), 0, 0, 0); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup of function %u failed", funcid); procform = (Form_pg_proc) GETSTRUCT(proctup); proname = NameStr(procform->proname); Assert(nargs == procform->pronargs); /* * 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. */ p_result = func_get_detail(makeList1(makeString(proname)), NIL, nargs, argtypes, &p_funcid, &p_rettype, &p_retset, &p_true_typeids); if (p_result != FUNCDETAIL_NOTFOUND && p_funcid == funcid) nspname = NULL; else nspname = get_namespace_name(procform->pronamespace); result = quote_qualified_identifier(nspname, proname); ReleaseSysCache(proctup); return result; } /* * generate_operator_name * Compute the name to display for an operator specified by OID, * given that it is being called with the specified actual arg types. * (Arg types matter because of ambiguous-operator resolution rules. * Pass InvalidOid for unused arg of a unary operator.) * * The result includes all necessary quoting and schema-prefixing, * plus the OPERATOR() decoration needed to use a qualified operator name * in an expression. */ static char * generate_operator_name(Oid operid, Oid arg1, Oid arg2) { StringInfoData buf; HeapTuple opertup; Form_pg_operator operform; char *oprname; char *nspname; Operator p_result; initStringInfo(&buf); opertup = SearchSysCache(OPEROID, ObjectIdGetDatum(operid), 0, 0, 0); if (!HeapTupleIsValid(opertup)) elog(ERROR, "cache lookup of operator %u failed", 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(makeList1(makeString(oprname)), arg1, arg2, true); break; case 'l': p_result = left_oper(makeList1(makeString(oprname)), arg2, true); break; case 'r': p_result = right_oper(makeList1(makeString(oprname)), arg1, true); break; default: elog(ERROR, "unexpected oprkind %c for operator %u", operform->oprkind, operid); 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)); } appendStringInfo(&buf, "%s", oprname); if (nspname) appendStringInfoChar(&buf, ')'); if (p_result != NULL) ReleaseSysCache(p_result); ReleaseSysCache(opertup); return buf.data; } /* * get_relid_attribute_name * Get an attribute name by its relations Oid and its attnum * * Same as underlying syscache routine get_attname(), except that error * is handled by elog() instead of returning NULL. */ static char * get_relid_attribute_name(Oid relid, AttrNumber attnum) { char *attname; attname = get_attname(relid, attnum); if (attname == NULL) elog(ERROR, "cache lookup of attribute %d in relation %u failed", attnum, relid); return attname; }