How to code stored procedures, functions, and triggers
Exercises
1. Write a script that creates and calls a stored procedure named spInsertCategory. First, code a statement that creates a procedure that adds a new row to the Categories table. To do that, this procedure should have one parameter for the category name.
Code at least two EXEC statements that test this procedure. (Note that this table doesn’t allow duplicate category names.)
2. Write a script that creates and calls a function named fnDiscountPrice that calculates the discount price of an item in the OrderItems 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.
3. Write a script that creates and calls a function named fnItemTotal that calculates the total amount of an item in the OrderItems table (discount price multiplied by quantity). To do that, this function should accept one parameter for the item ID, it should use the DiscountPrice function that you created in exercise 2, and it should return the value of the total for that item.
