From 3f8db37c2f1eeeffd9dae3189b783a463f56fe77 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 12 Aug 2006 20:05:56 +0000 Subject: [PATCH] Tweak SPI_cursor_open to allow INSERT/UPDATE/DELETE RETURNING; this was merely a matter of fixing the error check, since the underlying Portal infrastructure already handles it. This in turn allows these statements to be used in some existing plpgsql and plperl contexts, such as a plpgsql FOR loop. Also, do some marginal code cleanup in places that were being sloppy about distinguishing SELECT from SELECT INTO. --- doc/src/sgml/plperl.sgml | 52 +++++++++++----------------- doc/src/sgml/plpgsql.sgml | 27 +++++++++------ doc/src/sgml/spi.sgml | 28 ++++++++------- src/backend/commands/portalcmds.c | 4 +-- src/backend/executor/execMain.c | 4 +-- src/backend/executor/functions.c | 20 +++++++---- src/backend/executor/spi.c | 57 ++++++++++++++----------------- src/backend/optimizer/prep/prepjointree.c | 4 +-- src/backend/optimizer/util/clauses.c | 3 +- src/backend/parser/analyze.c | 11 +++++- src/backend/parser/parse_clause.c | 4 +-- src/backend/parser/parse_expr.c | 4 +-- src/backend/rewrite/rewriteDefine.c | 5 +-- src/backend/tcop/utility.c | 34 +++++++++++++++++- src/include/nodes/parsenodes.h | 5 +-- src/include/tcop/utility.h | 4 ++- 16 files changed, 152 insertions(+), 114 deletions(-) diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml index 12ac0157c3..32a7b12c71 100644 --- a/doc/src/sgml/plperl.sgml +++ b/doc/src/sgml/plperl.sgml @@ -1,4 +1,4 @@ - + PL/Perl - Perl Procedural Language @@ -244,18 +244,8 @@ $$ LANGUAGE plperl; SELECT * FROM perl_set(); - - - PL/Perl does not currently have full support for - domain types: it treats a domain the same as the underlying scalar - type. This means that constraints associated with the domain will - not be enforced. This is not an issue for function arguments, but - it is a hazard if you declare a PL/Perl function - as returning a domain type. - - If you wish to use the strict pragma with your code, the easiest way to do so is to SET @@ -439,26 +429,26 @@ SELECT * from lotsa_md5(500); The advantage of prepared queries is that is it possible to use one prepared plan for more - than one query execution. After the plan is not needed anymore, it must be freed with + than one query execution. After the plan is not needed anymore, it may be freed with spi_freeplan: CREATE OR REPLACE FUNCTION init() RETURNS INTEGER AS $$ - $_SHARED{my_plan} = spi_prepare( 'SELECT (now() + $1)::date AS now', 'INTERVAL'); + $_SHARED{my_plan} = spi_prepare( 'SELECT (now() + $1)::date AS now', 'INTERVAL'); $$ LANGUAGE plperl; CREATE OR REPLACE FUNCTION add_time( INTERVAL ) RETURNS TEXT AS $$ - return spi_exec_prepared( - $_SHARED{my_plan}, - $_[0], - )->{rows}->[0]->{now}; + return spi_exec_prepared( + $_SHARED{my_plan}, + $_[0], + )->{rows}->[0]->{now}; $$ LANGUAGE plperl; CREATE OR REPLACE FUNCTION done() RETURNS INTEGER AS $$ - spi_freeplan( $_SHARED{my_plan}); - undef $_SHARED{my_plan}; + spi_freeplan( $_SHARED{my_plan}); + undef $_SHARED{my_plan}; $$ LANGUAGE plperl; SELECT init(); @@ -478,16 +468,14 @@ SELECT done(); - spi_cursor_close can be used to abort sequence of - spi_fetchrow calls. Normally, the call to - spi_fetchrow that returns undef is - the signal that there are no more rows to read. Also - that call automatically frees the cursor associated with the query. If it is desired not - to read all retuned rows, spi_cursor_close must be - called to avoid memory leaks. + Normally, spi_fetchrow should be repeated until it + returns undef, indicating that there are no more + rows to read. The cursor is automatically freed when + spi_fetchrow returns undef. + If you do not wish to read all the rows, instead call + spi_cursor_close to free the cursor. + Failure to do so will result in memory leaks. - - @@ -630,8 +618,8 @@ CREATE FUNCTION badfunc() RETURNS integer AS $$ return 1; $$ LANGUAGE plperl; - The creation of this function will fail as its use of a forbidden - operation will be be caught by the validator. + The creation of this function will fail as its use of a forbidden + operation will be be caught by the validator. @@ -748,8 +736,8 @@ $$ LANGUAGE plperl; Name of the table on which the trigger fired. This has been deprecated, - and could be removed in a future release. - Please use $_TD->{table_name} instead. + and could be removed in a future release. + Please use $_TD->{table_name} instead. diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index ac5b2b4cfc..fb2fe735a6 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -1,4 +1,4 @@ - + <application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language @@ -2040,9 +2040,8 @@ END LOOP label ; The target is a record variable, row variable, or comma-separated list of scalar variables. The target is successively assigned each row - resulting from the query (which must be a - SELECT command) and the loop body is executed for each - row. Here is an example: + resulting from the query and the loop body is + executed for each row. Here is an example: CREATE FUNCTION cs_refresh_mviews() RETURNS integer AS $$ DECLARE @@ -2070,6 +2069,15 @@ $$ LANGUAGE plpgsql; + The query used in this type of FOR + statement can be any query that returns rows to the caller: + SELECT (without INTO) is the most common case, + but you can also use INSERT, UPDATE, or + DELETE with a RETURNING clause. Some utility + commands such as EXPLAIN will work too. + + + The FOR-IN-EXECUTE statement is another way to iterate over rows: @@ -2078,12 +2086,11 @@ FOR target IN EXECUTE text_expressionstatements END LOOP label ; - This is like the previous form, except that the source - SELECT statement is specified as a string - expression, which is evaluated and replanned on each entry to - the FOR loop. This allows the programmer to choose the speed of - a preplanned query or the flexibility of a dynamic query, just - as with a plain EXECUTE statement. + This is like the previous form, except that the source query + is specified as a string expression, which is evaluated and replanned + on each entry to the FOR loop. This allows the programmer to + choose the speed of a preplanned query or the flexibility of a dynamic + query, just as with a plain EXECUTE statement. diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml index 4430b3e4c7..016874dce7 100644 --- a/doc/src/sgml/spi.sgml +++ b/doc/src/sgml/spi.sgml @@ -1,4 +1,4 @@ - + Server Programming Interface @@ -535,15 +535,15 @@ typedef struct SPI_ERROR_TRANSACTION - if any command involving transaction manipulation was attempted - (BEGIN, - COMMIT, - ROLLBACK, - SAVEPOINT, - PREPARE TRANSACTION, - COMMIT PREPARED, - ROLLBACK PREPARED, - or any variant thereof) + if any command involving transaction manipulation was attempted + (BEGIN, + COMMIT, + ROLLBACK, + SAVEPOINT, + PREPARE TRANSACTION, + COMMIT PREPARED, + ROLLBACK PREPARED, + or any variant thereof) @@ -917,10 +917,12 @@ bool SPI_is_cursor_plan(void * plan) SPI_is_cursor_plan returns true if a plan prepared by SPI_prepare can be passed - as an argument to SPI_cursor_open and - false if that is not the case. The criteria are that the + as an argument to SPI_cursor_open, or + false if that is not the case. The criteria are that the plan represents one single command and that this - command is a SELECT without an INTO + command returns tuples to the caller; for example, SELECT + is allowed unless it contains an INTO clause, and + UPDATE is allowed only if it contains a RETURNING clause. diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c index 8b9dd99d4e..0685426a2f 100644 --- a/src/backend/commands/portalcmds.c +++ b/src/backend/commands/portalcmds.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.49 2006/08/08 01:23:15 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.50 2006/08/12 20:05:54 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -87,7 +87,7 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params) if (query->into) ereport(ERROR, - (errcode(ERRCODE_SYNTAX_ERROR), + (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), errmsg("DECLARE CURSOR may not specify INTO"))); if (query->rowMarks != NIL) ereport(ERROR, diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index 05c4a542b8..4b8a166ffa 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -26,7 +26,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.278 2006/08/12 02:52:04 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.279 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -497,7 +497,7 @@ InitPlan(QueryDesc *queryDesc, int eflags) /* * if there is a result relation, initialize result relation stuff */ - if (parseTree->resultRelation != 0 && operation != CMD_SELECT) + if (parseTree->resultRelation) { List *resultRelations = parseTree->resultRelations; int numResultRelations; diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c index 0da2abba77..28462ba8b8 100644 --- a/src/backend/executor/functions.c +++ b/src/backend/executor/functions.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/functions.c,v 1.104 2006/07/14 14:52:19 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/functions.c,v 1.105 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -361,7 +361,9 @@ postquel_getnext(execution_state *es) * run it to completion. (If we run to completion then * ExecutorRun is guaranteed to return NULL.) */ - if (LAST_POSTQUEL_COMMAND(es) && es->qd->operation == CMD_SELECT) + if (LAST_POSTQUEL_COMMAND(es) && + es->qd->operation == CMD_SELECT && + es->qd->parsetree->into == NULL) count = 1L; else count = 0L; @@ -868,7 +870,7 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList, JunkFilter **junkFilter) { Query *parse; - int cmd; + bool isSelect; List *tlist; ListCell *tlistitem; int tlistlen; @@ -893,15 +895,18 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList, /* find the final query */ parse = (Query *) lfirst(list_tail(queryTreeList)); - cmd = parse->commandType; - tlist = parse->targetList; + /* + * Note: eventually replace this with QueryReturnsTuples? We'd need + * a more general method of determining the output type, though. + */ + isSelect = (parse->commandType == CMD_SELECT && parse->into == NULL); /* * The last query must be a SELECT if and only if return type isn't VOID. */ if (rettype == VOIDOID) { - if (cmd == CMD_SELECT) + if (isSelect) ereport(ERROR, (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION), errmsg("return type mismatch in function declared to return %s", @@ -911,7 +916,7 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList, } /* by here, the function is declared to return some type */ - if (cmd != CMD_SELECT) + if (!isSelect) ereport(ERROR, (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION), errmsg("return type mismatch in function declared to return %s", @@ -921,6 +926,7 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList, /* * Count the non-junk entries in the result targetlist. */ + tlist = parse->targetList; tlistlen = ExecCleanTargetListLength(tlist); fn_typtype = get_typtype(rettype); diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c index c1f39f7c4f..6c4cc58546 100644 --- a/src/backend/executor/spi.c +++ b/src/backend/executor/spi.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.154 2006/08/12 02:52:04 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.155 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -837,26 +837,12 @@ SPI_cursor_open(const char *name, void *plan, planTree = (Plan *) linitial(ptlist); /* Must be a query that returns tuples */ - switch (queryTree->commandType) - { - case CMD_SELECT: - if (queryTree->into != NULL) - ereport(ERROR, - (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), - errmsg("cannot open SELECT INTO query as cursor"))); - break; - case CMD_UTILITY: - if (!UtilityReturnsTuples(queryTree->utilityStmt)) - ereport(ERROR, - (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), - errmsg("cannot open non-SELECT query as cursor"))); - break; - default: - ereport(ERROR, - (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), - errmsg("cannot open non-SELECT query as cursor"))); - break; - } + if (!QueryReturnsTuples(queryTree)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), + /* translator: %s is name of a SQL command, eg INSERT */ + errmsg("cannot open %s query as cursor", + CreateQueryTag(queryTree)))); /* Reset SPI result (note we deliberately don't touch lastoid) */ SPI_processed = 0; @@ -876,7 +862,7 @@ SPI_cursor_open(const char *name, void *plan, portal = CreatePortal(name, false, false); } - /* Switch to portals memory and copy the parsetree and plan to there */ + /* Switch to portal's memory and copy the parsetree and plan to there */ oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal)); queryTree = copyObject(queryTree); planTree = copyObject(planTree); @@ -919,9 +905,9 @@ SPI_cursor_open(const char *name, void *plan, * Set up the portal. */ PortalDefineQuery(portal, - NULL, + NULL, /* no statement name */ spiplan->query, - "SELECT", /* don't have the raw parse tree... */ + CreateQueryTag(queryTree), list_make1(queryTree), list_make1(planTree), PortalGetHeapMemory(portal)); @@ -954,9 +940,16 @@ SPI_cursor_open(const char *name, void *plan, */ PortalStart(portal, paramLI, snapshot); - Assert(portal->strategy == PORTAL_ONE_SELECT || - portal->strategy == PORTAL_ONE_RETURNING || - portal->strategy == PORTAL_UTIL_SELECT); + /* + * If this test fails then we're out of sync with pquery.c about + * which queries can return tuples... + */ + if (portal->strategy == PORTAL_MULTI_QUERY) + ereport(ERROR, + (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), + /* translator: %s is name of a SQL command, eg INSERT */ + errmsg("cannot open %s query as cursor", + CreateQueryTag(queryTree)))); /* Return the created portal */ return portal; @@ -1046,12 +1039,12 @@ SPI_getargcount(void *plan) /* * Returns true if the plan contains exactly one command - * and that command originates from normal SELECT (i.e. - * *not* a SELECT ... INTO). In essence, the result indicates - * if the command can be used with SPI_cursor_open + * and that command returns tuples to the caller (eg, SELECT or + * INSERT ... RETURNING, but not SELECT ... INTO). In essence, + * the result indicates if the command can be used with SPI_cursor_open * * Parameters - * plan A plan previously prepared using SPI_prepare + * plan: A plan previously prepared using SPI_prepare */ bool SPI_is_cursor_plan(void *plan) @@ -1070,7 +1063,7 @@ SPI_is_cursor_plan(void *plan) { Query *queryTree = (Query *) linitial((List *) linitial(qtlist)); - if (queryTree->commandType == CMD_SELECT && queryTree->into == NULL) + if (QueryReturnsTuples(queryTree)) return true; } return false; diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index ad128605dc..ef92d9d3c9 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -15,7 +15,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.41 2006/08/12 02:52:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.42 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -623,7 +623,6 @@ is_simple_subquery(Query *subquery) */ if (!IsA(subquery, Query) || subquery->commandType != CMD_SELECT || - subquery->resultRelation != 0 || subquery->into != NULL) elog(ERROR, "subquery is bogus"); @@ -686,7 +685,6 @@ is_simple_union_all(Query *subquery) /* Let's just make sure it's a valid subselect ... */ if (!IsA(subquery, Query) || subquery->commandType != CMD_SELECT || - subquery->resultRelation != 0 || subquery->into != NULL) elog(ERROR, "subquery is bogus"); diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 04f346d462..71e727a7b4 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.218 2006/08/12 02:52:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.219 2006/08/12 20:05:55 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -2689,7 +2689,6 @@ inline_function(Oid funcid, Oid result_type, List *args, */ if (!IsA(querytree, Query) || querytree->commandType != CMD_SELECT || - querytree->resultRelation != 0 || querytree->into || querytree->hasAggs || querytree->hasSubLinks || diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 61242ef712..39c7372733 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.345 2006/08/12 02:52:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.346 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -3116,6 +3116,15 @@ transformDeclareCursorStmt(ParseState *pstate, DeclareCursorStmt *stmt) /* Shouldn't get any extras, since grammar only allows SelectStmt */ if (extras_before || extras_after) elog(ERROR, "unexpected extra stuff in cursor statement"); + if (!IsA(stmt->query, Query) || + ((Query *) stmt->query)->commandType != CMD_SELECT) + elog(ERROR, "unexpected non-SELECT command in cursor statement"); + + /* But we must explicitly disallow DECLARE CURSOR ... SELECT INTO */ + if (((Query *) stmt->query)->into) + ereport(ERROR, + (errcode(ERRCODE_INVALID_CURSOR_DEFINITION), + errmsg("DECLARE CURSOR may not specify INTO"))); return result; } diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index d34529c74e..021fb3fa55 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.155 2006/07/26 19:31:51 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.156 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -447,7 +447,7 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) if (query->commandType != CMD_SELECT) elog(ERROR, "expected SELECT query from subquery in FROM"); - if (query->resultRelation != 0 || query->into != NULL) + if (query->into != NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("subquery in FROM may not have SELECT INTO"))); diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 6a7117e98b..0812c3d441 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.196 2006/08/02 01:59:46 joe Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.197 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1104,7 +1104,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink) elog(ERROR, "bad query in sub-select"); qtree = (Query *) linitial(qtrees); if (qtree->commandType != CMD_SELECT || - qtree->resultRelation != 0) + qtree->into != NULL) elog(ERROR, "bad query in sub-select"); sublink->subselect = (Node *) qtree; diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c index 3e1f65d868..df24c6751c 100644 --- a/src/backend/rewrite/rewriteDefine.c +++ b/src/backend/rewrite/rewriteDefine.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.111 2006/07/18 17:42:00 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.112 2006/08/12 20:05:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -264,7 +264,8 @@ DefineQueryRewrite(RuleStmt *stmt) * ... the one action must be a SELECT, ... */ query = (Query *) linitial(action); - if (!is_instead || query->commandType != CMD_SELECT) + if (!is_instead || + query->commandType != CMD_SELECT || query->into != NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("rules on SELECT must have action INSTEAD SELECT"))); diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 807b64360c..7d6941ddce 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.264 2006/08/12 02:52:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.265 2006/08/12 20:05:56 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1225,6 +1225,38 @@ UtilityTupleDescriptor(Node *parsetree) /* + * QueryReturnsTuples + * Return "true" if this Query will send output to the destination. + */ +bool +QueryReturnsTuples(Query *parsetree) +{ + switch (parsetree->commandType) + { + case CMD_SELECT: + /* returns tuples ... unless it's SELECT INTO */ + if (parsetree->into == NULL) + return true; + break; + case CMD_INSERT: + case CMD_UPDATE: + case CMD_DELETE: + /* the forms with RETURNING return tuples */ + if (parsetree->returningList) + return true; + break; + case CMD_UTILITY: + return UtilityReturnsTuples(parsetree->utilityStmt); + case CMD_UNKNOWN: + case CMD_NOTHING: + /* probably shouldn't get here */ + break; + } + return false; /* default */ +} + + +/* * CreateCommandTag * utility to get a string representation of the * command operation, given a raw (un-analyzed) parsetree. diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index f0f40e002e..222f5d26cc 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.322 2006/08/12 02:52:06 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.323 2006/08/12 20:05:56 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -89,7 +89,8 @@ typedef struct Query Node *utilityStmt; /* non-null if this is a non-optimizable * statement */ - int resultRelation; /* target relation (index into rtable) */ + int resultRelation; /* rtable index of target relation for + * INSERT/UPDATE/DELETE; 0 for SELECT */ RangeVar *into; /* target relation for SELECT INTO */ List *intoOptions; /* options from WITH clause */ diff --git a/src/include/tcop/utility.h b/src/include/tcop/utility.h index 09f96a262c..6674dec129 100644 --- a/src/include/tcop/utility.h +++ b/src/include/tcop/utility.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.27 2006/03/05 15:59:00 momjian Exp $ + * $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.28 2006/08/12 20:05:56 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -28,6 +28,8 @@ extern const char *CreateCommandTag(Node *parsetree); extern const char *CreateQueryTag(Query *parsetree); +extern bool QueryReturnsTuples(Query *parsetree); + extern bool QueryIsReadOnly(Query *parsetree); extern void CheckRelationOwnership(RangeVar *rel, bool noCatalogs); -- 2.11.0