hi.sorry to borther again I want to ask how to rewrite those statement ,too.
Like '>,<,LIMIT '. And when I use 'order by ' how to change the order of 'ASC,DESC'? Thanks very much. vanessa lee -----Original Message----- From: Roan Kattouw <roan.katt...@gmail.com> To: Wikimedia developers <wikitech-l@lists.wikimedia.org> Date: Thu, 26 Nov 2009 13:32:10 +0100 Subject: Re: [Wikitech-l] SQL 2009/11/26 Tim Starling <tstarl...@wikimedia.org>: > Don't use subselects, they're not supported by MySQL 4.0 which is what > we target. > > $dbr = wfGetDB( DB_SLAVE ); > > $max = $dbr->selectField( > 'recentchanges', > 'max(rc_id)', > false, > __METHOD__, > array( 'GROUP BY' => 'rc_title' ); > > $res = $dbr->select( > 'recentchanges', > '*', > array( > 'rc_id' => $max, > 'rc_namespace' => 0, > 'rc_title' => 'Wiki', > ), > __METHOD__ ); > Note that the GROUP BY condition in the first query is unnecessary, and that the whole thing could be rewritten to SELECT * FROM recentchanges WHERE rc_namespace=0 AND rc_title='Wiki' ORDER BY rc_id DESC LIMIT 1; Roan Kattouw (Catrope) _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
