On 2 Oct 2010, at 12:04am, Jim Mellander wrote: > I tried your trigger: > > CREATE TRIGGER auto_delete_summary AFTER DELETE ON detail > FOR EACH ROW WHEN NOT EXISTS (SELECT * FROM detail WHERE key = OLD.key) > BEGIN > DELETE FROM summary WHERE key = OLD.key; > END; > > and it works as advertised, but I would like to understand why. I'm a > bit hazy on why the FOR EACH ROW statement works. Does FOR EACH ROW > refer to each row that is being removed from 'detail'?
'FOR EACH ROW' reflects other possibilities defined in SQL which SQLite doesn't support right now. This page http://www.sqlite.org/lang_createtrigger.html describes what it means. The alternative would be 'FOR EACH STATEMENT' and the two would be different if one UPDATE command would make a change in more than one row in the database. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
