treasuredb/schema/triggers/enforcDebtImmutableOutsideTrigger.sql
2017-01-23 19:08:04 +01:00

13 lines
572 B
SQL

-- Prevent modification of paid value outside triggers which must adjust it exclusively
-- when new transfer records are inserted
CREATE TRIGGER enforceDebtImmutableOutsideTrigger
BEFORE UPDATE OF paid ON Debit
WHEN NOT EXISTS (SELECT * FROM Transfer t WHERE NEW.billId=t.billId AND amount IS NULL)
BEGIN
SELECT RAISE(FAIL, "paid is set and adjusted automatically according to added Transfer records")
WHERE (NEW.paid + IFNULL(
(SELECT m FROM __DO_NOT_MANIPULATE__trigger_memory WHERE c IS NULL AND d IS NULL), 0
) ) <> OLD.paid;
END;