Обсуждение: using case to select 'which version to use'

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

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;

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