Script to kill all connections to a database (More than RESTRICTED_USER ROLLBACK)

USE master
GO
ALTER DATABASE database_name
SET OFFLINE WITH ROLLBACK IMMEDIATE
GO

Ref: http://msdn.microsoft.com/en-us/library/bb522682%28v=sql.105%29.aspx

Updated

For MS SQL Server 2012 and above

USE [master];

DECLARE @kill varchar(8000) = '';  
SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), session_id) + ';'  
FROM sys.dm_exec_sessions
WHERE database_id  = db_id('MyDB')

EXEC(@kill);

For MS SQL Server 2000, 2005, 2008

USE master;

DECLARE @kill varchar(8000); SET @kill = '';  
SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), spid) + ';'  
FROM master..sysprocesses  
WHERE dbid = db_id('MyDB')

EXEC(@kill); 

You can get the script that SSMS provides by doing the following:

1. Right-click on a database in SSMS and choose delete
2. In the dialog, check the checkbox for "Close existing connections."
3. Click the Script button at the top of the dialog.

The script will look something like this:

USE [master]
GO
ALTER DATABASE [YourDatabaseName] SET  SINGLE_USER WITH ROLLBACK IMMEDIATE
GO
USE [master]
GO
DROP DATABASE [YourDatabaseName]
GO