On Mon, 11 Apr 2005, Peter Brawley wrote: >Thanks to Rhino & Dan for the corrections, HAVING in that query makes it >return only id values for which there is one row, and the header is >wrong since "first row of every group" doesn't mean anything without >explicit ordering.
What do you mean? > >PB > >----- > >Dan Bolser wrote: > >>On Mon, 11 Apr 2005, Rhino wrote: >> >> >> >>>----- Original Message ----- >>>From: "Dan Bolser" <[EMAIL PROTECTED]> >>>To: <mysql@lists.mysql.com> >>>Sent: Monday, April 11, 2005 5:58 AM >>>Subject: Display 1st row of every group? >>> >>> >>> >>> >>>>I read with great interest this >>>> >>>>http://www.artfulsoftware.com/queries.php#4 >>>> >>>>Display 1st row of every group >>>> >>>>SELECT id >>>>FROM tbl >>>>GROUP BY id >>>>HAVING count(*) = 1; >>>> >>>> >>>> >>>Despite what the heading says for that query, it is NOT going to return the >>>first row of every group. In fact, it is going to return only groups that >>>contain one row. For example, given this data: >>> >>>ID >>>-- >>>5 >>>5 >>>5 >>>6 >>>7 >>>7 >>>8 >>>8 >>>8 >>>9 >>> >>>That query will return return this: >>> >>>id >>>-- >>>6 >>>9 >>> >>>In other words, it is returning only groups where there is a single ID with >>>that value. Note also that it is returning ONLY an ID, not the ID plus the >>>rest of the row. Their description of what the query does is just plain >>>wrong. >>> >>> >> >>Delicious second opinion! >> >>Thanks for the reply - if you see my second post you see I fixed my >>problem. >> >>Cheers, >>Dan. >> >> >> >> > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
