SQL Aliases

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SQL aliases are used to temporarily rename a table or a column heading.

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SQL Aliases

SQL aliases are used to give a database table, or a column in a table, a temporary name.

Basically aliases are created to make column names more readable.

SQL Alias Syntax for Columns

SELECT column_name AS alias_name
FROM table_name;

SQL Alias Syntax for Tables

SELECT column_name(s)
FROM table_name AS alias_name;

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Demo Database

In this tutorial we will use the well-known Northwind sample database.

Below is a selection from the "Customers" table:

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
1	Alfreds Futterkiste	Maria Anders	Obere Str. 57	Berlin	12209	Germany
2	Ana Trujillo Emparedados y helados	Ana Trujillo	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Antonio Moreno	Mataderos 2312	México D.F.	05023	Mexico

And a selection from the "Orders" table:

OrderID	CustomerID	EmployeeID	OrderDate	ShipperID
10643	1	6	1997-08-25	1
10644	88	3	1997-08-25	2
10645	34	4	1997-08-26	1

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Alias Example for Table Columns

The following SQL statement specifies two aliases, one for the CustomerName column and one for the ContactName column. Tip: It require double quotation marks or square brackets if the column name contains spaces:

Example

SELECT CustomerName AS Customer, ContactName AS [Contact Person]
FROM Customers;

Try it yourself »

In the following SQL statement we combine four columns (Address, City, PostalCode, and Country) and create an alias named "Address":

Example

SELECT CustomerName, Address+', '+City+', '+PostalCode+', '+Country AS Address
FROM Customers;

Try it yourself »

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Alias Example for Tables

The following SQL statement selects all the orders from the customer "Alfreds Futterkiste". We use the "Customers" and "Orders" tables, and give them the table aliases of "c" and "o" respectively (Here we have used aliases to make the SQL shorter):

Example

SELECT o.OrderID, o.OrderDate, c.CustomerName
FROM Customers AS c, Orders AS o
WHERE c.CustomerName='Alfreds Futterkiste';

Try it yourself »

The same SQL statement without aliases:

Example

SELECT Orders.OrderID, Orders.OrderDate, Customers.CustomerName
FROM Customers, Orders
WHERE Customers.CustomerName='Alfreds Futterkiste';

Try it yourself »

Aliases can be useful when:

• There are more than one table involved in a query
• Functions are used in the query
• Column names are big or not very readable
• Two or more columns are combined together

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