Re: Simple function

On Tue, Dec 07, 2004 at 14:49:14 -0300,
  MaRCeLO PeReiRA <gandalf_mp@yahoo.com.br> wrote:
> Hi guys,
>
> I have a table with two integer fields (field1 and
> field2)...
>
> I would like to construct a function that perform an
> operation with this two fiels (field1 + fields2), and
> return the string value "A" if the sum is <20, "B" if
> the sum is >=20 or <=50, and finally return "C" if the
> sum is >50.

Why not use a CASE statement?

SELECT id,
  CASE
    WHEN field1 + field2 < 20 THEN 'A'
    WHEN field1 + field2 > 50 THEN 'C'
    ELSE 'B'
  END
  FROM mytable;"