SQL - ORDER BY

The ORDER BY clause comes in handy when you want to sort your SQL result sets by some column(s). For example if you want to select all the persons from the already familiar Customers table and order the result by date of birth, you will use the following statement:

SELECT * FROM Customers ORDER BY DOB

The result of the above SQL expression will be the following:

FirstName	LastName	Email	DOB	Phone
John	Smith	John.Smith@yahoo.com	2/4/1968	626 222-2222
Steven	Goldfish	goldfish@fishhere.net	4/4/1974	323 455-4545
Paula	Brown	pb@herowndomain.org	5/24/1978	416 323-3232
James	Smith	jim@supergig.co.uk	20/10/1980	416 323-8888

As you can see the rows are sorted in ascending order by the DOB column, but what if you want to sort them in descending order? To do that you will have to add the DESC keyword after your ORDER BY clause:

SELECT * FROM Customers ORDER BY DOB DESC

The result of the SQL query above will look like this:

FirstName	LastName	Email	DOB	Phone
James	Smith	jim@supergig.co.uk	20/10/1980	416 323-8888
Paula	Brown	pb@herowndomain.org	5/24/1978	416 323-3232
Steven	Goldfish	goldfish@fishhere.net	4/4/1974	323 455-4545
John	Smith	John.Smith@yahoo.com	2/4/1968	626 222-2222

If you don't specify how to order your rows, alphabetically or reverse, than the result set is ordered alphabetically, hence the following to SQL expressions produce the same result:

SELECT * FROM Customers ORDER BY DOB SELECT * FROM Customers ORDER BY DOB ASC

You can sort your result set by more than one column by specifying those columns in the ORDER BY list. The following SQL expression will order by DOB and LastName:

SELECT * FROM Customers ORDER BY DOB, LastName