Thread: Help in stored procedure

Help in stored procedure

From

"Igor Maciel Macaubas"

Date:

05 November 2004, 17:31:04

Hi Guys,

I need some help on building the following stored procedure, in PL/PgSQL. If this is not the right place to ask for help in this language, please let me know.

Here is what I want to do, my comments in red:

CREATE OR REPLACE FUNCTION discover_nsu(integer) RETURNS integer as '
DECLARE
    nsureturn integer;
    nsumax integer;
    caixaunitid alias for $1;
    branchid integer;
BEGIN
    branchid := select t1.branch as result from caixa.caixaunit as t1, caixa.caixa as t2 where t2.caixaunit = (select caixaunit from caixa.caixaunit where t2.id = caixaunitid);

-- the select above will return to me a result of one row and one column, with a integer variable inside, and will assign its result to branchid.

nsumax := select max(nsu) from caixa.view_transacao_agencia_nsu where branch = branchid;

-- here i'll use the var I discovered in the last select (branchid) and will do another select in a view (this view was previously created and works fine), and store the result of the query inside nsumax var.

IF (nsumax <= 0) OR (nsumax ISNULL) THEN

          nsureturn:=0;
    ELSE
          nsureturn:=nsumax + 1;
    END IF;
    RETURN nsureturn;

-- in the if-then-else above, i was just doing a simple test. If nsumax is equal or lower than 0, or nsumax is NULL, it'll assign 0 to the return var. Else, it'll get the max, add one, and assign the value to the return var, and finally, return it =)

END
' LANGUAGE 'plpgsql';

Okey, the function gets created fine b/c there are no sintax erros, the problem is when i try to execute:

database=> select discover_nsu(1);
ERROR: syntax error at or near "select" at character 9
QUERY: SELECT select t1.branch as result from caixa.caixaunit as t1, caixa.caixa as t2 where t2.caixaunit = (select caixaunit from caixa.cai
xaunit where t2.id = $1 )
CONTEXT: PL/pgSQL function "descobrir_nsu" line 7 at assignment
LINE 1: SELECT select t1.branch as result from caixa.caixaunit as t...
^

Well, the thing is: when I execute all the selects inside the stored procedure manually, they'll work, proving that there are no errors on the selects statements itself. I believe that the database cannot understand the type of the result, assuming that it's a row instead of a single record(??). I was looking at the PL/PgSQL reference manual and wasn't able to figure out a solution, so here I am .. can aonyone help me? Which type should I use to receive the return from the query? Are cast operations (for type conversions) supported in PL/PgSQL?

Thanks for all, please help!

Regards,

Igor
--
igor@providerst.com.br

Re: Help in stored procedure

From

Thomas F.O'Connell

Date:

05 November 2004, 18:14:43

I think you want to be using SELECT INTO rather than assignment for
your queries.

See

http://www.postgresql.org/docs/7.4/static/plpgsql-
statements.html#PLPGSQL-STATEMENTS-ASSIGNMENT
http://www.postgresql.org/docs/7.4/static/plpgsql-
statements.html#PLPGSQL-SELECT-INTO

The expression part of a basic assignment in PL/PgSQL is sent to be
executed in a SELECT, so you're basically saying "SELECT select"...

-tfo

--
Thomas F. O'Connell
Co-Founder, Information Architect
Sitening, LLC
http://www.sitening.com/
110 30th Avenue North, Suite 6
Nashville, TN 37203-6320
615-260-0005

On Nov 5, 2004, at 8:35 AM, Igor Maciel Macaubas wrote:

> Hi Guys,
>  
> I need some help on building the following stored procedure, in
> PL/PgSQL. If this is not the right place to ask for help in this
> language, please let me know.
> Here is what I want to do, my comments in red:
>  
> CREATE OR REPLACE FUNCTION discover_nsu(integer) RETURNS integer as '
> DECLARE
>     nsureturn integer;
>     nsumax integer;
>     caixaunitid alias for $1;
>     branchid integer;
> BEGIN
>     branchid := select t1.branch as result from caixa.caixaunit as t1,
> caixa.caixa as t2 where t2.caixaunit = (select caixaunit from
> caixa.caixaunit where t2.id = caixaunitid);
> -- the select above will return to me a result of one row and one
> column, with a integer variable inside, and will assign its result to
> branchid.
>
>     nsumax := select max(nsu) from caixa.view_transacao_agencia_nsu
> where branch = branchid;
> -- here i'll use the var I discovered in the last select (branchid)
> and will do another select in a view (this view was previously created
> and works fine), and store the result of the query inside nsumax  var.
>     IF (nsumax <= 0) OR (nsumax ISNULL) THEN
>           nsureturn:=0;
>     ELSE
>           nsureturn:=nsumax + 1;
>     END IF;
>     RETURN nsureturn;
> -- in the if-then-else above, i was just doing a simple test. If
> nsumax is equal or lower than 0, or nsumax is NULL, it'll assign 0 to
> the return var. Else, it'll get the max, add one, and assign the value
> to the return var, and finally, return it =)
>
>  
> END
> ' LANGUAGE 'plpgsql';
>  
> Okey, the function gets created fine b/c there are no sintax erros,
> the problem is when i try to execute:
>  
> database=> select discover_nsu(1);
> ERROR:  syntax error at or near "select" at character 9
> QUERY:  SELECT  select t1.branch as result from caixa.caixaunit as t1,
> caixa.caixa as t2 where t2.caixaunit = (select caixaunit from
> caixa.cai
> xaunit where t2.id =  $1 )
> CONTEXT:  PL/pgSQL function "descobrir_nsu" line 7 at assignment
> LINE 1: SELECT  select t1.branch as result from caixa.caixaunit as t...
>                 ^
> Well, the thing is: when I execute all the selects inside the stored
> procedure manually, they'll work, proving that there are no errors on
> the selects statements itself. I believe that the database cannot
> understand the type of the result, assuming that it's a row instead of
> a single record(??). I was looking at the PL/PgSQL reference manual
> and wasn't able to figure out a solution, so here I am .. can aonyone
> help me? Which type should I use to receive the return from the query?
> Are cast operations (for type conversions) supported in PL/PgSQL?
>  
> Thanks for all, please help!
>  
> Regards,
> Igor
> --
> igor@providerst.com.br
>