The SQL DISTINCT clause is used together with the SQL SELECT keyword, to return a dataset with unique entries for certain database table column.

We will use our Customers database table to illustrate the usage of SQL DISTINCT.

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

For example if we want to select all distinct surnames from our Customers table, we will use the following SQL DISTINCT statement:

SELECT DISTINCT LastName FROM Customers

The result of the SQL DISTINCT expression above will look like this:

LastName

Smith

Goldfish

Brown