Johannes,


without really having a look, what's happening, some notes:

> ALTER PROCEDURE CREATE_C_ENTRY (VA_ID VARCHAR(10))
> RETURNS (RC_ID INTEGER,
> RA_ID VARCHAR(10),
> RE_CODE VARCHAR(10))
> AS
>
> declare variable vE_CODE varchar(10);
> declare variable vC_ID integer;
> BEGIN
> for select e_code from table_a where id = :vA_ID into :vE_CODE do begin

vC_ID = NULL; /* add this line */

> select c_id from table_c where a_id = :vA_ID and e_code = :vE_CODE into :vC_ID;
>
> if (vC_ID is null) then begin

vC_ID is selected INSIDE in a single select which is inside a FOR SELECT
LOOP.
Then you ask if vcID IS NULL.
That might be the problem, since you don't initialize vcID inside your
loop, so that if your select (select c_id from table_c ) doesn't return
anything then vC_ID is not NULL, it has the value of the last loop
execution.
In general: If you select sth. that doesn't exist than the return value
is nothing (so your variable :vC_ID won't be touched). And nothing is
NOT equal to NULL.


Luc.