From 38255f2d0059a101c3fb791d6523a9e66e55aa66 Mon Sep 17 00:00:00 2001 From: Dean Rasheed Date: Tue, 10 Jan 2023 14:16:27 +0000 Subject: [PATCH] Fix MERGE's test for unreachable WHEN clauses. The former code would only detect an unreachable WHEN clause if it had an AND condition. Fix, so that unreachable unconditional WHEN clauses are also detected. Back-patch to v15, where MERGE was added. Discussion: https://postgr.es/m/CAEZATCVQ=7E2z4cSBB49jjeGGsB6WeoYQY32NDeSvcHiLUZ=ow@mail.gmail.com --- src/backend/parser/parse_merge.c | 6 +++--- src/test/regress/expected/merge.out | 2 +- src/test/regress/sql/merge.sql | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c index 62c2ff69f0c..e8865bfaf54 100644 --- a/src/backend/parser/parse_merge.c +++ b/src/backend/parser/parse_merge.c @@ -155,12 +155,12 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt) /* * Check for unreachable WHEN clauses */ - if (mergeWhenClause->condition == NULL) - is_terminal[when_type] = true; - else if (is_terminal[when_type]) + if (is_terminal[when_type]) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("unreachable WHEN clause specified after unconditional WHEN clause"))); + if (mergeWhenClause->condition == NULL) + is_terminal[when_type] = true; } /* diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out index 958fb85305c..21a82eefbcd 100644 --- a/src/test/regress/expected/merge.out +++ b/src/test/regress/expected/merge.out @@ -659,7 +659,7 @@ USING source AS s ON t.tid = s.sid WHEN MATCHED THEN /* Terminal WHEN clause for MATCHED */ DELETE -WHEN MATCHED AND s.delta > 0 THEN +WHEN MATCHED THEN UPDATE SET balance = t.balance - s.delta; ERROR: unreachable WHEN clause specified after unconditional WHEN clause ROLLBACK; diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql index 98fe1040bd4..fdbcd708823 100644 --- a/src/test/regress/sql/merge.sql +++ b/src/test/regress/sql/merge.sql @@ -438,7 +438,7 @@ USING source AS s ON t.tid = s.sid WHEN MATCHED THEN /* Terminal WHEN clause for MATCHED */ DELETE -WHEN MATCHED AND s.delta > 0 THEN +WHEN MATCHED THEN UPDATE SET balance = t.balance - s.delta; ROLLBACK;