From 19150be4b9f0fda7733d512f6090852c9f73d6b1 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 11 Aug 2022 13:17:58 +0200 Subject: [PATCH] Reject MERGE in CTE --- src/backend/parser/parse_cte.c | 7 +++++++ src/test/regress/expected/merge.out | 8 ++++++++ src/test/regress/sql/merge.sql | 5 +++++ 3 files changed, 20 insertions(+) diff --git a/src/backend/parser/parse_cte.c b/src/backend/parser/parse_cte.c index efb4af706e..8fc8658608 100644 --- a/src/backend/parser/parse_cte.c +++ b/src/backend/parser/parse_cte.c @@ -126,6 +126,13 @@ transformWithClause(ParseState *pstate, WithClause *withClause) CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc); ListCell *rest; + /* MERGE is allowed by parser, but unimplemented. Reject for now */ + if (IsA(cte->ctequery, MergeStmt)) + ereport(ERROR, + errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("MERGE not supported in WITH query"), + parser_errposition(pstate, cte->location)); + for_each_cell(rest, withClause->ctes, lnext(withClause->ctes, lc)) { CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(rest); diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out index af670e28e7..21609eba63 100644 --- a/src/test/regress/expected/merge.out +++ b/src/test/regress/expected/merge.out @@ -123,6 +123,14 @@ ON tid = tid WHEN MATCHED THEN DO NOTHING; ERROR: name "target" specified more than once DETAIL: The name is used both as MERGE target table and data source. +-- used in a CTE +WITH foo AS ( + MERGE INTO target USING source ON (true) +WHEN MATCHED THEN DELETE +) SELECT * FROM foo; +ERROR: MERGE not supported in WITH query +LINE 1: WITH foo AS ( + ^ -- unsupported relation types -- view CREATE VIEW tv AS SELECT * FROM target; diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql index afeb212f3c..a3e9d36fe3 100644 --- a/src/test/regress/sql/merge.sql +++ b/src/test/regress/sql/merge.sql @@ -88,6 +88,11 @@ MERGE INTO target USING target ON tid = tid WHEN MATCHED THEN DO NOTHING; +-- used in a CTE +WITH foo AS ( + MERGE INTO target USING source ON (true) +WHEN MATCHED THEN DELETE +) SELECT * FROM foo; -- unsupported relation types -- view -- 2.30.2