Sams Teach Yourself SQL in 10 Minutes, Second Edition

Understanding Views

Views are virtual tables. Unlike tables that contain data, views simply contain queries that dynamically retrieve data when used.

The best way to understand views is to look at an example. Back in Lesson 12, “Joining Tables,” you used the following SELECT statement to retrieve data from three tables:

SELECT cust_name, cust_contact
FROM Customers, Orders, OrderItems
WHERE Customers.cust_id = Orders.cust_id
        AND OrderItems.order_num = Orders.order_num
        AND prod_id = 'RGAN01';

That query was used to retrieve the customers who had ordered a specific product. Anyone needing this data would have to understand the table structure, as well as how to create the query and join the tables. To retrieve the same data for another product ...