CREATE OR REPlACE PROCEDURE DELETE_CUSTOMER
(CUSTOMER_ID NUMBER) AS
TOT_CUSTOMERS NUMBER;
BEGIN
    DELETE FROM CUSTOMERS
    WHERE CUSTOMERS.CUSTOMER_ID = DELETE_CUSTOMER.CUSTOMER_ID;
    TOT_CUSTOMERS := TOT_CUSTOMERS - 1;
    END;
/

EXECUTE DELETE_CUSTOMER(01);

Error starting at line : 120 in command -
BEGIN DELETE_CUSTOMER(01); END;
Error report -
ORA-02292: integrity constraint (TUG81959.ORDERS_FK_CUSTOMERS) violated - child record found
ORA-06512: at "TUG81959.DELETE_CUSTOMER", line 5
ORA-06512: at line 1
02292. 00000 - "integrity constraint (%s.%s) violated - child record found"
*Cause:    attempted to delete a parent key value that had a foreign
           dependency.
*Action:   delete dependencies first then parent or disable constraint.

CREATE OR REPlACE PROCEDURE DELETE_CUSTOMER
(CUSTOMER_ID_IN NUMBER) AS
TOT_CUSTOMERS NUMBER;
CURSOR C1 IS
DELETE FROM ORDERS
WHERE ORDERS.ORDER_ID = CUSTOMER_ID.ORDER_ID;
CURSOR C2 IS
DELETE FROM ORDER_DETAILS
WHERE ORDER_DETAILS.ORDER_ID = CUSTOMER_ID.ORDER_ID;
CURSOR C3 IS
DELETE FROM CUSTOMERS
WHERE CUSTOMERS.CUSTOMER_ID = DELETE_CUSTOMER.CUSTOMER_ID;
BEGIN
    OPEN C1;
    OPEN C2;
    OPEN C3;
    IF C1%FOUND AND C2%FOUND AND C3%FOUND
    THEN TOT_CUSTOMERS := TOT_CUSTOMERS - 1;
    END IF;
    CLOSE C1;
    CLOSE C2;
    CLOSE C3;
END;
/