Problems creating a function

Hi List,

I was wondering if someone could help me out. I'm migrating a Oracle db to
PostgreSQL so I must rewrite the functions 'cuz the PL/pgSQL's sintax is
different. The problem is to sum dates .. as follows:

CREATE FUNCTION ft_vcto_dupl(NUMERIC,NUMERIC,TIMESTAMP,NUMERIC,TIMESTAMP)
RETURNS TIMESTAMP AS '
DECLARE
pEmp ALIAS FOR $1;
pFil ALIAS FOR $2;
pDataEmissao ALIAS FOR $3;
pCodigoPrazoPgto ALIAS FOR $4;
pPrazoPgtoFixo ALIAS FOR $5;
mDataVctoDupl TIMESTAMP := pPrazoPgtoFixo;
mPrazoPgto NUMERIC(3) := 0;
BEGIN
SELECT INTO mPrazoPgto prazo FROM ftpraz00 WHERE emp = pEmp AND fil = 0
AND codigo = pCodigoPrazoPgto;
IF NVL(to_number(TO_CHAR(mDataVctoDupl,''MM'')),00) = 00 THEN
***** mDataVctoDupl := pDataEmissao + mPrazoPgto;
END IF;
--
RETURN (mDataVctoDupl);
END;

' LANGUAGE 'plpgsql'

In the line marked with " ***** " it should be something like :

mDataVctoDupl := pDataEmissao + interval ''mPrazoPgto day'';

BUT , this way the PostgreSQL treats the variable mPrazoPgto as a string
and it must treat it like a variable and use its value.

How do I make it understand mPrazoPgto as variable ?

Atenciosamente,

Rhaoni Chiu Pereira
Sistêmica Computadores

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