G-7720 – Never use multiple UPDATE OF in trigger event clause.

A DML trigger can have multiple triggering events separated by `or` like `before insert or delete or update of some_column`. If you have multiple `update of` separated by `or`, only one of them (the last one) is actually used and you get no error message, so you have a bug waiting to happen. Instead you always should use a single `update of` with all columns comma-separated, or an `update` without `of` if you wish all columns.

Tags: Stored Object.

Quality area: Maintainability. Severity: Blocker. Fixing time: Local-medium.