The SQL SELECT DISTINCT Statement

Use : In a table, some of the columns may contain duplicate values. This is not a problem, however, sometimes you will want to list only the different (distinct) values in a table.

 

The DISTINCT keyword can be used to return only distinct (different) values.

Syntax

SELECT DISTINCT column_name(s)
FROM table_name

 

SELECT DISTINCT Example

The "Persons" table:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes
2 Svendson Tove Borgvn 23 Sandnes
3 Pettersen Kari Storgt 20 Stavanger

Now we want to select only the distinct values from the column named "City" from the table above.

We use the following SELECT statement:

SELECT DISTINCT City FROM Persons

The result-set will look like this:

City
Sandnes
Stavanger

 

 

copyright @2008 Punuptech.com