Sams Teach Yourself SQL in 10 Minutes, Second Edition

Using Table Aliases

Back in Lesson 7, “Creating Calculated Fields,” you learned how to use aliases to refer to retrieved table columns. The syntax to alias a column looks like this:

SELECT RTRIM(vend_city)+', '+RTRIM(vend_state)+' '+RTRIM(vend_zip) AS address2
FROM Vendors
ORDER BY vend_name;

In addition to using aliases for column names and calculated fields, SQL also enables you to alias table names. There are two primary reasons to do this:

• To shorten the SQL syntax

• To enable multiple uses of the same table within a single SELECT statement

Take a look at the following SELECT statement. It is basically the same statement as an example used in the previous lesson, but it has been modified to use aliases:

 SELECT cust_name, cust_contact FROM ...