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From:Peter Lauri Date:June 21 2006 8:42am
Subject:RE: if else statement
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SELECT IF(col1=3, (Select col2 from table2 where table2.id = 1), (Select
col2 from table3 where table3.id = 1)) FROM table1 WHERE id=1;

That should do it.

-----Original Message-----
From: Thomas Lundström [mailto:zodin@stripped] 
Sent: Wednesday, June 21, 2006 7:51 PM
To: Song Ken Vern-E11804
Cc: mysql@stripped
Subject: Re: if else statement

Not sure what you're aming for here and how your data is structured but
why not use a join and alias and fetch all info in one select and then
solve what you need in your code?

Something in the line of:

select t2.col2 from_t2, t3.col2 from_t3 
from table1 t1, table2 t2, table3 t3 
where t1.id = t2.id 
  and t1.id = t3.id
  and t1.id = 3

Maybe you can do something like that?

Regards,

Thomas L.


ons 2006-06-21 klockan 17:16 +0800 skrev Song Ken Vern-E11804:
> Hi,
>  
> I'm trying to build a query in using SQL instead of doing it in Perl. 
> 
> I am trying to do something like this : 
> 
> If ((select col1 from table1 where id = 1) == 3)
> Then 
> Select col2 from table2 where table2.id = 1;
> Else
> Select col2 from table3 where table3.id = 1;
> 
> In Perl I would probably do have to access the DB twice. 
> 
> Select col2 from table1 where if = 1; 
> 
> If (col2 == 3) { 
>  Select col2 from table2 where table2.id = 1;
> } else { 
>  Select col2 from table3 where table3.id = 1;
> }
> 
> I've read the manual on subqueries but the example don't indicate how I
> can 
> do a conditional test using a subquery?
> 
> Am I on the right track or is there another way to do this?
> 
> Thanks
> 
> --
> Ken
> e11804
> 



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Thread
if else statementSong Ken Vern-E1180421 Jun
  • Re: if else statementJørn Dahl-Stamnes21 Jun
  • Re: if else statementThomas Lundström21 Jun
    • RE: if else statementPeter Lauri21 Jun
RE: if else statementSong Ken Vern-E1180423 Jun
  • Re: if else statementMichael Stassen23 Jun
    • Re: if else statementThomas Lundström25 Jun