Re: calling currval() before nextval() patch adding - Mailing list pgsql-patches

On Sun, 2004-11-07 at 17:21, John Hansen wrote:
> Hi list,
>
> attached, cvs context diff that adds currval_isset('sequence_name');


> With this patch, I can now call currval_isset to determine if I need to
> call currval. Previously, I just called currval, but with the result of
> filling up the server log with warnings.

This might do what you're looking for on 8.0.

CREATE OR REPLACE FUNCTION currval_isset(text) RETURNS bigint AS '
DECLARE
  var integer;
BEGIN
  SELECT currval($1) INTO var;

  RETURN var;

EXCEPTION
  WHEN     OBJECT_NOT_IN_PREREQUISITE_STATE THEN
    RETURN 0;
END;
' LANGUAGE plpgsql;

SELECT isset('tst_seq');