On Tue, Jun 24, 2008 at 2:14 PM, Ben Reece <[EMAIL PROTECTED]> wrote: > INSERT INTO List1 (name, email, unsubbed) (SELECT name, email, 'N' FROM > List2 LEFT JOIN List1 ON List2.email = List1.email WHERE List1.email IS > NULL) > > That should prevent it from inserting any email address from List2 that's > already in List1.
A better solution to prevent duplicates is to enforce the uniqueness. Add a UNIQUE key for the email address column. This will prevent all duplicates all the time. With that in place combining the list is even simpler: INSERT IGNORE INTO List1 (name, email, unsubbed) (SELECT name, email, 'N', FROM List2) That will just ignore rows that duplicate the email address. _______________________________________________ UPHPU mailing list [email protected] http://uphpu.org/mailman/listinfo/uphpu IRC: #uphpu on irc.freenode.net
