Question

SQL Triggers: PESOFT P NOTE POO IS DOCE ESTE GIS DAN DISINI OS ARRANCE US PHONE QUS BALANCE WOO PARCE P DISCOUNT V OGLE VALE VONTACT VAREATCOS VEMONE V SAE VORCER SED IN DATE P ORDE UNE UNITS UPER BP NE BPNTAL PP 14 DATE VENTA DE BP VOR Create a trigger called named trg_prod QOH_on_line_add that will automatically update the product quantity on hand for a product when a corresponding product LINE row is added. We end a trigger with a slash (l) on a line by itself (see below). Also, remember to always use the COMMIT: command after you create, drop or replace a trigger. A template has been created for you below for this trigger. Fill in the ... areas with the proper code: CREATE OR REPLACE TRIGGER trg prod_QOH_on_line_add BEFORE INSERT ON LINE FOR EACH ROW BEGIN UPDATE SET WHERE END COMMIT

Answer 1

Answer)

CREATE OR REPLACE TRIGGER trg_prod_QOH_on_line_add
BEFORE INSERT ON LINE
FOR EACH ROW
BEGIN
UPDATE PRODUCT
SET P_QOH = :NEW.LINE_UNITS+P_QOH
WHERE PRODUCT.P_CODE = :NEW.P_CODE;
END;

EXPLANATION

When we insert a new row in the table, in trigger we catch it by :NEW keyword. SO in this I use that, when a new insert is happened in LINE table, just that time, P_QOH = :NEW.LINE_UNITS+P_QOH, it means that P_QOH is updated in the product table by the value inserted(NEW.LINE_UNITS) with the old value of PQH in product table.