The following tables form part of a database held in a relational DBMS (Primary Key,Foreign Key):

Item (Item _ID, Item_Name, Item_Price)

Customer (Customer_No, L_Name, F_Name, Address, Type)

CustomerItem (Customer_No, Item_No, Date_Purchased)

Employee (Employee_No L_Name, F_Name, Role)

Give the relational algebra (not SQL) expressions for the following queries (3.75 marks each):

2. Show the Customer(s) who did not purchase any item (*Show the Customer_No only)
4. Show the name of items purchased by "VIP" Customers
6. Show the "Wholesale" Customers who have purchased any item on 01-01-2022 (*Show the Customer_No only)
8. Examine the following relational algebra, and answer the following questions:

Customer_No, L_Name (Customer)

L_Name, Employee_No (Employee)

2. Why is the relational algebra statement above incorrect?
4. Rewrite the statement to correct the error