Another Function Question

Question

I have created the following Function:
CREATE FUNCTION f_defer_future_payments
(Vendor_id varchar2,
User_id varchar2,
Start_date date,
End_date date,
Defer_to_date date
RETURN NUMBER
IS
original_start_date date;
original_end_date date;
original_defer_to_date date;
dfp_start_date_flag char(1);
start_date_changed number(5);
start_date_chgd_fut_to_future number(5);
start_date_chgd_past_to_future number(5);
defer_to_date_changed number(5);
update_vehicle_processing number(5);
update_vendor_data number(5);
today_date date;
min_date date;
return_code number;
test_flag_internal number(5);
lv_db_session_id number(18,0);
BEGIN
start_date_chgd_past_to_future := 0;
start_date_chgd_fut_to_future := 0;
update_vehicle_processing := 0;
update_vendor_data := 0;
today_date := TRUNC(SYSDATE);
min_date := TO_DATE('18000101','YYYYMMDD');
return_code :=
CASE dfp_start_date_flag
WHEN 'Y' THEN 2
WHEN 'N' THEN 1
ELSE 1
END;
IF ((original_defer_to_date IS NOT NULL) AND (Defer_to_date IS NULL)) THEN
update_vehicle_processing := 1;
Defer_to_date := NULL;
update_vendor_data := 0;
return_code :=
CASE dfp_start_date_flag
WHEN 'Y' THEN 2
WHEN 'N' THEN 1
END;
END IF;
-- ============================================================
-- Process finished with SUCCESS
-- ============================================================
RETURN(1);
END;
When I try to compile it, I get this error:
NAME TYPE SEQUENCE LINE POSITION
TEXT
ATTRIBUTE MESSAGE_NUMBER
F_DEFER_FUTURE_PAYMENTS FUNCTION 1 43 8
PLS-00363: expression 'DEFER_TO_DATE' cannot be used as an assignment target
ERROR 363
F_DEFER_FUTURE_PAYMENTS FUNCTION 2 43 8
PL/SQL: Statement ignored
ERROR 0
2 rows selected.
In this Function, I need to set the passed variable 'Defer_to_date' to NULL; why can't I do this??
Any Assistance would be appreciated.
Murray Sobol

Answer 1

there is no need to change the parameter value since you will not use it back to the calling program. if you need to return the parameter value back to your calling program switch to procedure and define the parameter variable as in and out.