On Tue, Jul 03, 2012 at 01:32:14PM +0200, Paul van Helden scratched on the wall: > Hi, > > Is this correct? Should update triggers not only fire for actual changes? I > have a large table with a column which contains all NULL values except for > 4. I expected an UPDATE table SET column=NULL to only fire 4 triggers, > except it fires for every row.
The statement "UPDATE table SET column=NULL" updates every row in the table. The fact that some rows may already have a NULL in that column is not important. If you only want the trigger to fire for non-NULL rows, you need to update only the non-NULL rows: UPDATE table SET column=NULL WHERE column IS NOT NULL; As for sqlite3_changes() returning 0, that doesn't sound right unless you're checking inside the trigger. -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "Intelligence is like underwear: it is important that you have it, but showing it to the wrong people has the tendency to make them feel uncomfortable." -- Angela Johnson _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users