Message-ID: <4A8EE3D5.3050501@fmed.uba.ar>
Date: Fri, 21 Aug 2009 15:13:41 -0300
From: Gerardo Herzig <gherzig@fmed.uba.ar>
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To: =?UTF-8?B?IlJvZHJpZ28gRS4gRGUgTGXDs24gUGxpY2V0Ig==?= <rdeleonp@gmail.com>
CC: pgsql-sql@postgresql.org
Subject: Re: using case to select 'which version to use'
References: <4A8D6912.60207@fmed.uba.ar>
	<a55915760908200933p5740cb21i4fcb37f1ea8eb242@mail.gmail.com>
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Rodrigo E. De León Plicet wrote:
> On Thu, Aug 20, 2009 at 10:17 AM, Gerardo Herzig<gherzig@fmed.uba.ar> wrote:
>> Hi all. I have 2 functions , which returns the same columns, but with
>> tottaly different logics. I want to wrap it with a third function, who
>> will receive a boolean argument to decide wich sub-function have to use.
>>
>> I want to use case, so i dont have to use pl/pgsql.
>>
>> This is a non-working example:
>>
>>
>> CREATE OR REPLACE FUNCTION get_oferta(varchar, varchar, varchar, bool,
>> OUT cod varchar , OUT description varchar)
>> returns setof record
>> security definer
>> as
>> $$
>> select  * from case $4 when true then
>>    (select * from get_oferta_from_a($1, $2, $3))
>> else
>>    (select * from get_oferta_from_b($1, $2, $3))
>> end;
>> $$ language sql;
>>
>> Can i use case for a case like this?
>>
>> Thanks!
>> Gerardo
> 
> Try:
> 
> SELECT *
> FROM get_oferta_from_a ($1, $2, $3)
> WHERE $4
> UNION ALL
> SELECT *
> FROM get_oferta_from_b ($1, $2, $3)
> WHERE NOT $4;
> 
> 
Well, looks like it will work. I think i found the right syntax now:

select foo.* from
  (select case $4 when false then
      get_oferta_from_a($1, $2, $3)
  else
      get_oferta_from_b($1, $2, $3)
  end) as foo;

Thanks!

Gerardo