mysql - i am trying to update quantity of product when order is placed but sql is returning garbage value when trying to fetch current value

Question

product table orderitem table

    BEGIN
    DECLARE var integer;
    SELECT stock INTO var FROM product WHERE pno = new.pid;
    UPDATE product SET s=var,product.stock= var - new.quantity WHERE pno = 
    new.pid;
    END

i am trying to update quantity of product when order is placed but sql is returning garbage value when trying to fetch current value

Answer 1

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