On 10/15/2013 01:38 PM, Quang Thoi wrote:
I want to roll back deletion if there is a reference (FK) in another table. Can I explicitly call a rollback inside a function?
No. Transactions are controlled outside the body of any executing function. You do have have a couple other options, though. If you can't use a basic foreign key which does this automatically, you can have your trigger function return NULL. From the documentation:
"Row-level triggers fired BEFORE can return null to signal the trigger manager to skip the rest of the operation for this row (i.e., subsequent triggers are not fired, and the INSERT/UPDATE/DELETE does not occur for this row)"
You could also raise an explicit error so the user sees something. To fake a foreign key violation, you'd do:
RAISE EXCEPTION foreign_key_violation; So you don't need a rollback anyway. -- Shaun Thomas OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604 312-676-8870 sthomas@xxxxxxxxxxxxxxxx ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
