Informix Error -734

Reasons / Common Causes

-734 fires in three related naming-collision situations, per the official guidance: the triggering table (or a synonym for it) has the same name as the OLD/NEW correlation name in the REFERENCING clause; a table or synonym referenced in the triggered action matches either correlation name; or the OLD correlation name matches the NEW correlation name.

1. The triggering table's name coinciding with the chosen correlation name, per the official guidance — for example, REFERENCING NEW AS orders on a trigger for the orders table itself.
2. A table/synonym referenced within the triggered action sharing a name with a correlation name, per the official guidance — an unrelated naming collision inside the action clause.
3. OLD and NEW given the same correlation name, per the official guidance — the two must be distinguishable.

Solutions / Resolution

1. Change either the correlation name or the table name, per the official guidance's documented resolution, and resubmit the CREATE TRIGGER statement.
2. Pick correlation names clearly distinct from any table/synonym name involved, as a general practice to avoid this collision — conventional short prefixes like pre/post (as used elsewhere in this reference) avoid the problem entirely.
3. Give OLD and NEW different correlation names, if they were accidentally set to the same one.

Examples

A correlation name matching the triggering table

CREATE TRIGGER trg_orders_update UPDATE OF status ON orders
  REFERENCING NEW AS orders FOR EACH ROW
  (EXECUTE PROCEDURE log_status_change(orders.status));
-- -734: 'orders' collides with the triggering table's own name

Corrected

CREATE TRIGGER trg_orders_update UPDATE OF status ON orders
  REFERENCING NEW AS post FOR EACH ROW
  (EXECUTE PROCEDURE log_status_change(post.status));

Diagnostic Checks

1. Compare the chosen OLD/NEW correlation names against the triggering table's name, any synonym for it, and any table/synonym referenced in the triggered action, and against each other.

Related Errors / Related Topics

• -732 — "Incorrect use of old or new values correlation name inside trigger." A related REFERENCING restriction, about how the correlation name is used rather than a naming collision.

Pick correlation names clearly distinct from any table/synonym name involved, and from each other — the official guidance's own fix is simply to rename one side of the collision.