diff options
| -rw-r--r-- | src/backend/commands/tablecmds.c | 18 | ||||
| -rw-r--r-- | src/test/regress/expected/foreign_key.out | 13 | ||||
| -rw-r--r-- | src/test/regress/sql/foreign_key.sql | 13 |
3 files changed, 44 insertions, 0 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index f97bee5b0e4..6322fa75a76 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -7723,6 +7723,24 @@ ATExecDropConstraint(Relation rel, const char *constrName, is_no_inherit_constraint = con->connoinherit; /* + * If it's a foreign-key constraint, we'd better lock the referenced + * table and check that that's not in use, just as we've already done + * for the constrained table (else we might, eg, be dropping a trigger + * that has unfired events). But we can/must skip that in the + * self-referential case. + */ + if (con->contype == CONSTRAINT_FOREIGN && + con->confrelid != RelationGetRelid(rel)) + { + Relation frel; + + /* Must match lock taken by RemoveTriggerById: */ + frel = heap_open(con->confrelid, AccessExclusiveLock); + CheckTableNotInUse(frel, "ALTER TABLE"); + heap_close(frel, NoLock); + } + + /* * Perform the actual constraint deletion */ conobj.classId = ConstraintRelationId; diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out index 46a30b44289..fef072eddfa 100644 --- a/src/test/regress/expected/foreign_key.out +++ b/src/test/regress/expected/foreign_key.out @@ -1401,4 +1401,17 @@ rollback to x; commit; -- fail ERROR: insert or update on table "fktable2" violates foreign key constraint "fktable2_f1_fkey" DETAIL: Key (f1)=(2) is not present in table "pktable2". +-- +-- Test that we prevent dropping FK constraint with pending trigger events +-- +begin; +insert into fktable2 values(2); +alter table fktable2 drop constraint fktable2_f1_fkey; +ERROR: cannot ALTER TABLE "fktable2" because it has pending trigger events +commit; +begin; +delete from pktable2 where f1 = 1; +alter table fktable2 drop constraint fktable2_f1_fkey; +ERROR: cannot ALTER TABLE "pktable2" because it has pending trigger events +commit; drop table pktable2, fktable2; diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql index cc36ab5bafc..5f19dad03cd 100644 --- a/src/test/regress/sql/foreign_key.sql +++ b/src/test/regress/sql/foreign_key.sql @@ -1041,4 +1041,17 @@ delete from fktable2; rollback to x; commit; -- fail +-- +-- Test that we prevent dropping FK constraint with pending trigger events +-- +begin; +insert into fktable2 values(2); +alter table fktable2 drop constraint fktable2_f1_fkey; +commit; + +begin; +delete from pktable2 where f1 = 1; +alter table fktable2 drop constraint fktable2_f1_fkey; +commit; + drop table pktable2, fktable2; |