Creating a trigger that updates a table using data from two different tables - sql

Question

OK, so I'm now trying to create a trigger that helps to update a summary table that contains a product id, total sales, and total quantity of items per product. Essentially, I need to create a trigger that fires after the update of an order, when the orderplaced column is set to a value of '1' the summary table will need to be updated by a fired trigger grabbing the data from two other tables which are basket and basketitem to reference the idproduct. I have created the code but for more that i think of it and analyze it, i can't get to an valid compiled trigger that works. I will be adding my code so you can have an idea of what I'm trying to do here. thanks!
create or replace
TRIGGER BB_SALESUM_TRG
AFTER UPDATE OF orderplaced ON BB_BASKET
DECLARE
CURSOR salesum_cur IS
SELECT bi.idproduct as idp, sum(b.total) as tot, sum(b.quantity) as qua,
bi.orderplaced as orpl
FROM bb_basket b, bb_basketitem bi
WHERE b.idbasket = bi.idbasket;
BEGIN
FOR rec_cur IN salesum_cur LOOP
IF rec_cur.orpl = 1 THEN
INSERT INTO bb_sales_sum (idproduct, tot_sales, tot_qty)
VALUES (rec_cur.idp, rec_cur.tot, rec_cur.qua));
END IF;
END LOOP;
END;
I have tried it in different ways, this is the last one I have though. I was also trying with using local variables instead of a cursor but neither way worked, any suggestions are very welcome !
thanks !

Answer 1

If I understand your requirements correctly, the following PL/SQL should point you in the right direction. I was unable to test this:
CREATE OR REPLACE TRIGGER BB_SALESUM_TRG
AFTER UPDATE OF orderplaced ON BB_BASKET
FOR EACH ROW
WHEN (new.orderplaced = 1)
BEGIN
INSERT INTO bb_sales_sum(idproduct, tot_sales, tot_qty number)
SELECT idproduct, sum(b.total), sum(b.quantity)
FROM bb_basket b INNER JOIN bb_basketitem bi
ON b.idbasket = bi.idbasket
WHERE b.idbasket = :new.idbasket
GROUP BY idproduct
END;