-----Original Message----- From: Claire Lee [mailto:jing...@yahoo.com] Sent: Tuesday, September 27, 2005 2:48 PM To: mys...@lists.mysql.com Subject: strange order by problem

I need to order a few names by the number following the main name. For example swap2, swap3, swap10 in the order of swap2, swap3, swap10, not in swap10, swap2, swap3 as it will happen when I do an order by.

So I came up with the following query:

mysql> select distinct secname, date from optresult where secname like 'swap%' and date like '2005-09-2%' order by if (secname like 'swap%',(right(secname,lengt h(secname)-locate('p',secname))+0), secname);

I was hoping it will order by the number following each 'swap' in the secname, it doesn't work. It was ordered instead by secname.

+----------+------------+ | secname | date | +----------+------------+ | SWAP0.25 | 2005-09-21 | | SWAP0.5 | 2005-09-21 | | SWAP1 | 2005-09-21 | | SWAP10 | 2005-09-26 | | SWAP10 | 2005-09-23 | | SWAP10 | 2005-09-21 | | SWAP2 | 2005-09-26 | | SWAP2 | 2005-09-23 | | SWAP2 | 2005-09-22 | | SWAP2 | 2005-09-21 | | SWAP3 | 2005-09-21 | | SWAP3 | 2005-09-26 | | SWAP3 | 2005-09-23 | | SWAP3 | 2005-09-22 | | SWAP5 | 2005-09-21 | | SWAP5 | 2005-09-26 | | SWAP5 | 2005-09-23 | | SWAP5 | 2005-09-22 | +----------+------------+

However, if I replace the second expression in the if statement by date, like the following, it's ordered by date as I would expect.

mysql> select distinct secname, date from optresult where secname like 'swap%' and date like '2005-09-2%' order by if (secname like 'swap%',date, secname); +----------+------------+ | secname | date | +----------+------------+ | SWAP3 | 2005-09-21 | | SWAP0.5 | 2005-09-21 | | SWAP5 | 2005-09-21 | | SWAP1 | 2005-09-21 | | SWAP10 | 2005-09-21 | | SWAP2 | 2005-09-21 | | SWAP0.25 | 2005-09-21 | | SWAP2 | 2005-09-22 | | SWAP3 | 2005-09-22 | | SWAP5 | 2005-09-22 | | SWAP10 | 2005-09-23 | | SWAP2 | 2005-09-23 | | SWAP3 | 2005-09-23 | | SWAP5 | 2005-09-23 | | SWAP10 | 2005-09-26 | | SWAP2 | 2005-09-26 | | SWAP3 | 2005-09-26 | | SWAP5 | 2005-09-26 | +----------+------------+

So I tried different combinations of the second and third expressions in the if statement in the query, the next one is the only one I can get it to order my way, which is not what I wanted of course since I don't want other secnames than swap% to order this way.

mysql> select distinct secname, date from optresult where secname like 'swap%' and date like '2005-09-2%' order by if (secname like 'swap%',(right(secname, leng th(secname)-locate('p', secname))+0), right(secname,length(secname)-locate('p',secname))+0); +----------+------------+ | secname | date | +----------+------------+ | SWAP0.25 | 2005-09-21 | | SWAP0.5 | 2005-09-21 | | SWAP1 | 2005-09-21 | | SWAP2 | 2005-09-22 | | SWAP2 | 2005-09-26 | | SWAP2 | 2005-09-21 | | SWAP2 | 2005-09-23 | | SWAP3 | 2005-09-22 | | SWAP3 | 2005-09-26 | | SWAP3 | 2005-09-21 | | SWAP3 | 2005-09-23 | | SWAP5 | 2005-09-23 | | SWAP5 | 2005-09-22 | | SWAP5 | 2005-09-26 | | SWAP5 | 2005-09-21 | | SWAP10 | 2005-09-26 | | SWAP10 | 2005-09-21 | | SWAP10 | 2005-09-23 | +----------+------------+

Can anyone see what problems I have in my query? I'm really stuck here. Thanks.

Claire