Function PostgreSQL 9.2

Hi all,

I've got two tables:

- users
- companies

I'm trying to create a function that:

- if users.code is empty, it gives a default value
- And the increment_client_code in company should auto increment for the
next client code

What I've done so far:

DROP FUNCTION IF EXISTS client_code_increment_count();
> CREATE OR REPLACE FUNCTION "public"."client_code_increment_count" ()
> RETURNS TABLE("code" INT) AS
> $BODY$
> SELECT MAX(CAST(users.code AS INT)) FROM users WHERE users.code ~ '^\d+$'
> AND company_id = 2
> $BODY$
> LANGUAGE sql;
> SELECT * FROM "client_code_increment_count"();

CREATE OR REPLACE FUNCTION "public"."auto_generate_client_code_if_empty" ()
> RETURNS "trigger"
> VOLATILE
> AS $dbvis$
> BEGIN
> END;
> $dbvis$ LANGUAGE plpgsql;

> CREATE TRIGGER "increment_client_code"
> BEFORE INSERT OR UPDATE ON users
> FOR EACH ROW
> EXECUTE PROCEDURE "auto_generate_client_code_if_empty"();

But still can't do that works.. What Am I missing?

Cheers