Обсуждение: Need help with plpgsql function.

Hi,

I'm creating the function on a postgres 8.2 server.
I would like the function to accept half a dozen varied parameters (varchars
and timestamps).
The first parameter will determine which one of the 6 different select
queries that function is going to run.

The function will return all the rows from the chosen select statement.

I've been reading the postgresql documentation in creating functions that
returns rowset and I've read about  plpgsql. It seems to be what I need
because there is going to be conditional statements.

I'm just having a hard time putting it all together, and I'm not sure about
the syntax and how to return the selected rows back into OUT parameters.

This is a short pseudo example:

CREATE OR REPLACE FUNCTION report (
-- function arguments, type will determine which one of the 6 queries to run IN type       character varying(20), IN
param1  character varying(255), IN param2   timestamp,
 
-- returned values OUT code          table.code%TYPE, OUT name         table.name%TYPE
)
RETURNS SETOF rows
{ LANGUAGE PLPGSQL
IF type like 'type A' THEN   SELECT code, name INTO rows FROM tableA join some table ....;   return rows
ELSIF type like 'type B' THEN   SELECT code, name INTO rows FROM tableB join someothertable ... ;   return rows
ELSE   RETURN VOID
END IF;
}







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2010/11/14 berelith <nicolasbeuzeboc@gmail.com>:
>
> Hi,
>
> I'm creating the function on a postgres 8.2 server.
> I would like the function to accept half a dozen varied parameters (varchars
> and timestamps).
> The first parameter will determine which one of the 6 different select
> queries that function is going to run.
>
> The function will return all the rows from the chosen select statement.
>
> I've been reading the postgresql documentation in creating functions that
> returns rowset and I've read about  plpgsql. It seems to be what I need
> because there is going to be conditional statements.
>
> I'm just having a hard time putting it all together, and I'm not sure about
> the syntax and how to return the selected rows back into OUT parameters.
>
> This is a short pseudo example:
>
> CREATE OR REPLACE FUNCTION report (
> -- function arguments, type will determine which one of the 6 queries to run
>  IN type       character varying(20),
>  IN param1   character varying(255),
>  IN param2   timestamp,
> -- returned values
>  OUT code          table.code%TYPE,
>  OUT name         table.name%TYPE
> )
> RETURNS SETOF rows
> { LANGUAGE PLPGSQL
> IF type like 'type A' THEN
>    SELECT code, name INTO rows FROM tableA join some table ....;
>    return rows
> ELSIF type like 'type B' THEN
>    SELECT code, name INTO rows FROM tableB join someothertable ... ;
>    return rows
> ELSE
>    RETURN VOID
> END IF;
> }
>
>

Hello

you can use a RETURN QUERY statement - some like

CREATE OR REPLACE FUNCTION foo(IN i int, OUT a int, OUT b int)
RETURNS SETOF RECORD AS $$
BEGIN IF i = 1 THEN   RETURN QUERY SELECT 10,20 UNION ALL SELECT 30,40; ELSE   RETURN QUERY SELECT 60,70 UNION ALL
SELECT80,90; END IF; RETURN; 
END;
$$ LANGUAGE plpgsql;

SELECT * FROM foo(1);
SELECT * FROM foo(2);

Regards

Pavel Stehule


>
>
>
>
>
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> View this message in context:
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>
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On Saturday 13 November 2010 11:15:51 pm Pavel Stehule wrote:

> > }
>
> Hello
>
> you can use a RETURN QUERY statement - some like
>
> CREATE OR REPLACE FUNCTION foo(IN i int, OUT a int, OUT b int)
> RETURNS SETOF RECORD AS $$
> BEGIN
>   IF i = 1 THEN
>     RETURN QUERY SELECT 10,20 UNION ALL SELECT 30,40;
>   ELSE
>     RETURN QUERY SELECT 60,70 UNION ALL SELECT 80,90;
>   END IF;
>   RETURN;
> END;
> $$ LANGUAGE plpgsql;
>
> SELECT * FROM foo(1);
> SELECT * FROM foo(2);
>
> Regards
>
> Pavel Stehule
>

FYI the OP is using 8.2 :) RETURN QUERY is 8.3+ 

-- 
Adrian Klaver
adrian.klaver@gmail.com

2010/11/14 Adrian Klaver <adrian.klaver@gmail.com>:
> On Saturday 13 November 2010 11:15:51 pm Pavel Stehule wrote:
>
>> > }
>>
>> Hello
>>
>> you can use a RETURN QUERY statement - some like
>>
>> CREATE OR REPLACE FUNCTION foo(IN i int, OUT a int, OUT b int)
>> RETURNS SETOF RECORD AS $$
>> BEGIN
>>   IF i = 1 THEN
>>     RETURN QUERY SELECT 10,20 UNION ALL SELECT 30,40;
>>   ELSE
>>     RETURN QUERY SELECT 60,70 UNION ALL SELECT 80,90;
>>   END IF;
>>   RETURN;
>> END;
>> $$ LANGUAGE plpgsql;
>>
>> SELECT * FROM foo(1);
>> SELECT * FROM foo(2);
>>
>> Regards
>>
>> Pavel Stehule
>>
>
> FYI the OP is using 8.2 :) RETURN QUERY is 8.3+

sorry :)

then

RETURN QUERY query -->

DECLARE r record;
BEGIN  FOR r IN SELECT ....    RETURN NEXT r;  END FOR;
...

Regards

Pavel Stehule


>
> --
> Adrian Klaver
> adrian.klaver@gmail.com
>