thank you for your answer, the function is declared as:
FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2))
i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact,
i would not want to loose precision because that is money, is there any other way which does not
involve loosing precision ? thankS!!
> From: tgl@sss.pgh.pa.us
> To: jpablolorenzetti@hotmail.com
> CC: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
> Date: Tue, 22 Sep 2015 16:07:36 -0400
>
> "Juan Pablo L." <jpablolorenzetti@hotmail.com> writes:
> > Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
> > inside the function i can not read the parameter or so it seems, this what is do:
>
> > float8 db_balance,in_chgval;
>
> > in_chgval = PG_GETARG_FLOAT8(2);
>
> > elog(INFO,"in_chgval = %0.2f",in_chgval);
>
> If the C code is written that way, the function has to be declared to take
> type float8 (a/k/a double precision), not numeric.
>
> The parser will insert a conversion from numeric to float8 automatically,
> so the function will still work with a numeric data column. You might
> lose some precision in the conversion though.
>
> regards, tom lane