Re: if in a select
Date: 1996/02/22
Message-ID: <4ghvqa$o7b_at_wagner.spc.videotron.ca>#1/1
W.van.der.Deijl_at_inter.nl.net (Wilfred van der Deijl) wrote:
>vgwlu_at_chevron.com (greg w. luft) wrote:
>>Is there any way to do an if statement list conditional within a select statement?
>>Greg
>No there is not.
>BUT: You can use a decode to get something like
>IF var=value1 THEN
> result := res1;
>ELSIF var=value2 THEN
> result := res2;
>ELSE
> result := res3;
>END IF;
>You can get this by:
>SELECT DECODE(var, value1, res1
> , value2, res2
> , res3)
>FROM DUAL;
>If you have a PL/SQL like this:
>IF a < b THEN
> result := res1;
>ELSE
> result := res2;
>END IF;
>Than you might want to use this:
>SELECT DECODE (SIGN(A-B), -1, res1
> , res2)
>FROM DUAL;
>Or if you want to make it a part of the WHEN-clause
>SELECT something
>FROM sometable
>WHERE SIGN(A-B) = -1;
>This is based on the following:
> A < B
>--> A - B < 0
>--> SIGN(A-B) = -1
>The same is:
> A <= B
>--> A - B <= 0
>--> SIGN(A-B) = 0 or -1
>--> SIGN(A-B)-1 = -1 or -2
>--> SIGN(SIGN(A-B)-1) = -1 the value -1 will indicate that A<=B
>>--
>>Greg Luft Phone: (403) 234-5570
>>Chevron Canada Resources Email: gwlu_at_chevron.com
>>500 5th Ave
>>Calgary Alberta
>Bye,
>Wilfred
>The Netherlands
>=======================================================
>E-mail : W.van.der.Deijl_at_inter.nl.net
>Homepage: http://www.inter.nl.net/users/W.van.der.Deijl
> (including the MicroProse Grand Prix II FAQ!)
You can use the DECODE Function
Benoit Stephenson
Benoit.Stephenson_at_dmr.ca Received on Thu Feb 22 1996 - 00:00:00 CET