> not all the rows, only the distinct q_id, The subquery will give all distinct q_ids, but the select from in(subquery) will give everything, because each row must have a q_id which is returned by the subquery. The query after all says "select all rows where the q_id is one of the q_ids occuring in the table" and this, of course, gives everything. Also your select qid, max(atimestamp) is not doing what I think you want to do. I think you want all raws where atimestamp is somehow a maximum. Now in your query max(atimesamp) will return one single value and this will be used as a sort of constant. So if max(atimestamp) is e. g. 5, you get effictively select qid, 5 from ... Qou will get all rows with the constant becoming a row. You want to filter rows, so your condition must be in where (this is a basic concept of sql). Somehow (this is not correct sql, just a hint) it must be like select qid from kkk where atimestamp=max(atimestamp). If you want to filter the condition must be in where, a function on a column behins select will not filter. I think you need to get a basic understanding of sql first, sorry if that sounds harsh Stefan
On Wed, Mar 13, 2013 at 8:28 PM, Johan De Meersman <vegiv...@tuxera.be>wrote: > ------------------------------ > > *From: *"Ananda Kumar" <anan...@gmail.com> > *Subject: *Re: Retrieve most recent of multiple rows > > > > select qid,max(atimestamp) from kkk where qid in (select distinct qid from > kkk) group by qid; > > > What use is that where statement? It just says to use all the rows in the > table. > > > -- > Unhappiness is discouraged and will be corrected with kitten pictures. > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
