The Simple Machine

With SQL, an alias name can be given to a table or to a column. This can be a good thing to do if you have very long or complex table names or column names.

An alias name could be anything, but usually it is short.

SYNTAX FOR TABLES

SELECT column_name(s)

FROM table_name

AS alias_name

SYNTAX FOR COLUMNS

SELECT column_name AS alias_name

FROM table_name

EXAMPLE

Assume we have a table called “Persons” and another table called “Product_Orders”. We will give the table aliases of “p” and “po” respectively.

Say we want to list all the orders that “Ola Hansen” is responsible for.

We use the following SELECT statement:

SELECT po.OrderID, p.LastName, p.FirstName

FROM Persons AS p,

Product_Orders AS po

WHERE p.LastName=’Hansen’ AND p.FirstName=’Ola’

The same SELECT statement without aliases:

SELECT Product_Orders.OrderID, Persons.LastName, Persons.FirstName

FROM Persons,

Product_Orders

WHERE Persons.LastName=’Hansen’ AND Persons.FirstName=’Ola’

As you’ll see from the two SELECT statements above; aliases can make queries easier to both write and to read.