diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2006-06-21 18:30:19 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2006-06-21 18:30:19 +0000 |
| commit | 62ae14545b35798fcb51bfd0aa9b5038ad6a07ff (patch) | |
| tree | 15bdbb7ec8c8edad6ca2973797b7196cd3a1d628 | |
| parent | e582d2ee1a149502f49c7a337707b4a0f940a51d (diff) | |
| download | postgresql-62ae14545b35798fcb51bfd0aa9b5038ad6a07ff.tar.gz postgresql-62ae14545b35798fcb51bfd0aa9b5038ad6a07ff.zip | |
Disallow aggregate functions in UPDATE commands (unless within a sub-SELECT).
This is disallowed by the SQL spec because it doesn't have any very sensible
interpretation. Historically Postgres has allowed it but behaved strangely.
As of PG 8.1 a server crash is possible if the MIN/MAX index optimization gets
applied; rather than try to "fix" that, it seems best to just enforce the
spec restriction. Per report from Josh Drake and Alvaro Herrera.
| -rw-r--r-- | src/backend/parser/analyze.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index da8629bbb36..52515630bef 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.326.2.1 2005/11/22 18:23:12 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.326.2.2 2006/06/21 18:30:19 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2333,9 +2333,16 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt) qry->jointree = makeFromExpr(pstate->p_joinlist, qual); qry->hasSubLinks = pstate->p_hasSubLinks; - qry->hasAggs = pstate->p_hasAggs; + + /* + * Top-level aggregates are simply disallowed in UPDATE, per spec. + * (From an implementation point of view, this is forced because the + * implicit ctid reference would otherwise be an ungrouped variable.) + */ if (pstate->p_hasAggs) - parseCheckAggregates(pstate, qry); + ereport(ERROR, + (errcode(ERRCODE_GROUPING_ERROR), + errmsg("cannot use aggregate function in UPDATE"))); /* * Now we are done with SELECT-like processing, and can get on with |