Hi i am updating a table called 'shipping' using the following code:

Code:
DECLARE
        v_shid NUMBER := &sv_shippid;
        v_invid NUMBER := &sv_inventoryid;
        v_quan_ex NUMBER := &sv_quantity_expected;
BEGIN
        INSERT INTO shipping (shipid, invid, quantity_expected)
        VALUES  (v_shid, v_invid, v_quan_ex);

commit;

UPDATE shipping
                SET date_expected = SYSDATE + 7
        WHERE   shipid = v_shid;

END;
/
description of table;

Code:
SQL> describe shipping
 Name                            Null?    Type
 ------------------------------- -------- ----
 SHIPID                          NOT NULL NUMBER(10)
 INVID                           NOT NULL NUMBER(10)
 DATE_EXPECTED            NOT NULL DATE
 QUANTITY_EXPECTED      NOT NULL NUMBER(4)
 DATE_RECEIVED                            DATE
 QUANTITY_RECEIVED                    NUMBER(4)
When i execute the script i can enter a new shipping id, inventory id and amount. However when i press enter after i enter amount, i get the following error message:

Code:
SQL> @q3.sql
Enter value for sv_shippid: 233
old   2:        v_shid NUMBER := &sv_shippid;
new   2:        v_shid NUMBER := 233;
Enter value for sv_inventoryid: 11772
old   3:        v_invid NUMBER := &sv_inventoryid;
new   3:        v_invid NUMBER := 11772;
Enter value for sv_quantity_expected: 200
old   4:        v_quan_ex NUMBER := &sv_quantity_expected;
new   4:        v_quan_ex NUMBER := 200;
DECLARE
*
ERROR at line 1:
ORA-01400: cannot insert NULL into ("W1009048"."SHIPPING"."DATE_EXPECTED")
ORA-06512: at line 6
Can som1 tell me why i get the error message even though i am entering data in the amount section.