Mysql触发器不起作用

Question

I have been searching all around about TRIGGERS since I am in dire needs for some of them, but it doesn't matter how much I try Mysql workbench 6.3 CE won't allow me to create it. It seems like my server is 5.7 and I have read the manual for references but I still can't make them to work.

DELIMITER $$
CREATE TRIGGER updateproductostock
BEFORE INSERT ON producto
FOR EACH ROW
BEGIN
NEW.prod_points = prod_price / 2;
END$$
DELIMITER ;

I have a table named producto which has id, description, price, stock and points. What I want to do is to have the points value to be the half of the price value. So if the price of a product is $100 then the points value will be 50.

I cant create the trigger, mysql gives me syntax error.

I also would like to make a trigger in which the stock value of producto depends on the table order . Order has an order id, product id, description and quantity. So when I insert a new order I want to have the value of stock in producto to change. If an order is made with the same id of the product then I want the quantity of the order to be added to the stock of the product .

Again, mysql gives me syntax error.

I have searched all over the place and tried different kinds of syntax but I get error. My mysql does have the option for trigger.

Or perhaps is there an easier way to do what i want to do? Please help

Answer 1

For the sql you've shown, I would guess prod_price / 2 should be NEW.prod_price / 2 .

For the latter issue, the trigger needs to be on the order table; but it is generally frowned on maintaining such values when they should be easily calculable unless there is a pressing performance reason to do so. My guess with your problems with that would be that your order table is named with a keyword and you are forgetting to delimit it properly with `.