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From:Gleb Paharenko Date:December 5 2005 10:19am
Subject:Re: About union sql Mysql 4.x
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Hello.

From http://dev.mysql.com/doc/refman/5.0/en/union.html:

"ORDER BY for individual SELECT statements within parentheses has an
effect only when combined with LIMIT. Otherwise, the ORDER BY is
optimized away."


Therefore you're getting the same results, because ORDER BY doen't
work for your query.



HALIL DEMIREZEN wrote:
> Hi,
> 
> I am trying to run an sql query such as below to list items=x randomly and 
> then items != x randomly.. 
> 
> 
> mysql> (select * from tablea where item=1 order by rand()) union all 
> (select  * from tablea where item != 1 order by rand());
> 
> but the result is not as expected. rand() seems not to be working...
> 
> What can be the problem? or what can be the difference between my will and 
> the exact result of the query?
> 
> Thanks..
>  
> 
> ------------------------------------------------------------
> Halil Demirezen 
> System Support Engineer/ Sistem Destek Muhendisi 
> Mobile Tel/Cep Tel: +90(543) 502 04 42
> E-Mail/E-Posta: halil.demirezen@stripped
> -----------------------------------------------------------
> 


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Thread
About union sql Mysql 4.xHALIL DEMIREZEN5 Dec
  • Re: About union sql Mysql 4.xGleb Paharenko5 Dec
    • Re: About union sql Mysql 4.xHALIL DEMIREZEN5 Dec
      • Re: About union sql Mysql 4.xGleb Paharenko5 Dec
Re: About union sql Mysql 4.xMichael Stassen5 Dec
  • Re: About union sql Mysql 4.xHALIL DEMIREZEN5 Dec
Re: About union sql Mysql 4.xMichael Stassen5 Dec