diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index c5fe6b6a3fd..8f697f85ec5 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -1665,11 +1665,16 @@ transformWindowDefinitions(ParseState *pstate, /* * Per spec, a windowdef that references a previous one copies the * previous partition clause (and mustn't specify its own). It can - * specify its own ordering clause. but only if the previous one had + * specify its own ordering clause, but only if the previous one had * none. It always specifies its own frame clause, and the previous - * one must not have a frame clause. (Yeah, it's bizarre that each of + * one must not have a frame clause. Yeah, it's bizarre that each of * these cases works differently, but SQL:2008 says so; see 7.11 - * <window clause> syntax rule 10 and general rule 1.) + * <window clause> syntax rule 10 and general rule 1. The frame + * clause rule is especially bizarre because it makes "OVER foo" + * different from "OVER (foo)", and requires the latter to throw an + * error if foo has a nondefault frame clause. Well, ours not to + * reason why, but we do go out of our way to throw a useful error + * message for such cases. */ if (refwc) { @@ -1708,11 +1713,27 @@ transformWindowDefinitions(ParseState *pstate, wc->copiedOrder = false; } if (refwc && refwc->frameOptions != FRAMEOPTION_DEFAULTS) + { + /* + * Use this message if this is a WINDOW clause, or if it's an OVER + * clause that includes ORDER BY or framing clauses. (We already + * rejected PARTITION BY above, so no need to check that.) + */ + if (windef->name || + orderClause || windef->frameOptions != FRAMEOPTION_DEFAULTS) + ereport(ERROR, + (errcode(ERRCODE_WINDOWING_ERROR), + errmsg("cannot copy window \"%s\" because it has a frame clause", + windef->refname), + parser_errposition(pstate, windef->location))); + /* Else this clause is just OVER (foo), so say this: */ ereport(ERROR, (errcode(ERRCODE_WINDOWING_ERROR), - errmsg("cannot override frame clause of window \"%s\"", - windef->refname), + errmsg("cannot copy window \"%s\" because it has a frame clause", + windef->refname), + errhint("Omit the parentheses in this OVER clause."), parser_errposition(pstate, windef->location))); + } wc->frameOptions = windef->frameOptions; /* Process frame offset expressions */ wc->startOffset = transformFrameOffset(pstate, wc->frameOptions, |