SQL Server Management Studio: Set a Database to Single-user Mode

This topic describes how to set a user-defined database to single-user mode by using Object Explorer in SQL Server Management Studio. Single-user mode specifies that only one user at a time can access the database and is generally used for maintenance actions.

Caution

If other users are connected to the database at the time that you set the database to single-user mode, their connections to the database will be closed without warning.

The database remains in single-user mode even if the user that set the option logs off. At that point, a different user, but only one, can connect to the database.

To set a database to single-user mode

1. In Object Explorer, connect to an instance of the SQL Server Database Engine, and then expand that instance.
2. Right-click the database to change, and then click Properties.
3. In the Database Properties dialog box, click the Options page.
4. From the Restrict Access option, select Single.
5. If other users are connected to the database, an Open Connections message will appear. To change the property and close all other connections, click Yes.
6. 
   

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Pasted from <http://technet.microsoft.com/en-us/library/ms345598.aspx>