diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2010-10-02 18:21:41 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2010-10-02 18:21:41 -0400 |
| commit | 1f0b62e8c28026f5d1d3693087f7b4aef6a191af (patch) | |
| tree | 4b19501703245505629a1ea4d8a228fd68d2e096 | |
| parent | 50595b5fce2e15b5ef26b057799b4a4cdd1c10e8 (diff) | |
Throw an appropriate error if ALTER COLUMN TYPE finds a dependent trigger.
Actually making this case work, if the column is used in the trigger's
WHEN condition, will take some new code that probably isn't appropriate
to back-patch. For now, just throw a FEATURE_NOT_SUPPORTED error rather
than allowing control to reach the "unexpected object" case. Per bug #5688
from Daniel Grace. Back-patch to 9.0 where the possibility of such a
dependency was introduced.
| -rw-r--r-- | src/backend/commands/tablecmds.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index a5d7af60420..403e55af917 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -6411,6 +6411,24 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, colName))); break; + case OCLASS_TRIGGER: + /* + * A trigger can depend on a column because the column is + * specified as an update target, or because the column is + * used in the trigger's WHEN condition. The first case would + * not require any extra work, but the second case would + * require updating the WHEN expression, which will take a + * significant amount of new code. Since we can't easily tell + * which case applies, we punt for both. FIXME someday. + */ + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter type of a column used in a trigger definition"), + errdetail("%s depends on column \"%s\"", + getObjectDescription(&foundObject), + colName))); + break; + case OCLASS_DEFAULT: /* @@ -6431,7 +6449,6 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, case OCLASS_OPFAMILY: case OCLASS_AMOP: case OCLASS_AMPROC: - case OCLASS_TRIGGER: case OCLASS_SCHEMA: case OCLASS_TSPARSER: case OCLASS_TSDICT: |