Sams Teach Yourself SQL in 10 Minutes, Second Edition

Creating Views

So now that you know what views are (and the rules and restrictions that govern them), let's look at view creation.

Views are created using the CREATE VIEW statement. Like CREATE TABLE, CREATE VIEW can only be used to create a view that does not exist. To overwrite a view you must first DROP it and then recreate it.

Using Views to Simplify Complex Joins

One of the most common uses of views is to hide complex SQL, and this often involves joins. Look at the following statement:

CREATE VIEW ProductCustomers AS
SELECT cust_name, cust_contact, prod_id
FROM Customers, Orders, OrderItems
WHERE Customers.cust_id = Orders.cust_id
         AND OrderItems.order_num = Orders.order_num;

This statement creates a view named ProductCustomers, which ...