SQLite Forum

DROP COLUMN feature with indexes
> On a related note, I'm not sure how much schema checking SQLite does for triggers, but CREATE TRIGGER x BEFORE UPDATE OF z ON c1 also remains unmodified after a column is dropped.

Good eye! This is a special case, because SQLite never checks for or complains about unknown column names in the "UPDATE OF" clause of a trigger. If the column being dropped is used anywhere else in the trigger it should be an error.