For SQL homework, I$\text{'}$m working on this question:

Write a script that creates and calls a stored function named discount$\_$price that calculates the discount price of an item in the Order$\_$Items table $($discount amount subtracted from item price$).$ To do that, this function should accept one parameter for the item ID$,$ and it should return the value of the discount price for that item. Execute the query and take a screenshot of the query and the results.

So this is the code I tried, but it doesn't seem to work:

DELIMITER $//$

CREATE FUNCTION discount$\_$price

$($

itemIdParam INT

$)$

RETURNS DECIMAL$(9,2)$

BEGIN

DECLARE varDiscountPrice DECIMAL$(9,2)$;

SELECT item$\_$price$-$discount$\_$amount

INTO varDiscountPrice

FROM Order$\_$Items

WHERE itemId$=$ itemIdParam;

RETURN varDiscountPrice;

END$//$

DELIMITER;

and the error I also got is also attached. Did I perform a coding error or is my solution incorrect?