If I have two tables, T1 and T2, such that both have the same primary key of "user_id". What is the SQL I would use to delete all rows from T1 that are not in T2?
This is one way to write the SQL but it is really inefficient: DELETE FROM T1 WHERE T1.user_id NOT IN (SELECT user_id FROM T2 WHERE T2.user_id=T1.user_id); I was thinking there should be a way to write this with a join. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 [University of Illinois at Urbana-Champaign logo]<http://illinois.edu/>
<<inline: image003.png>>
