SQL Server Kill All Connections

Killing all connections in SQL Server is something that you may need to do from time to time. The two times that I’ve needed to do this most is when I’m restoring a database in my test environment or when I need to rename a database. Both of these operations require that there are not any open connections to the SQL Server database. There are a couple good scripts that I will show here. My favored method is to set it in single user mode.

 
Kill All Connections Using Single User Mode
This is the easiest way kill all the connections to the database. It basically sets the database to only allow 1 user (you) and it will kill all the other connections.

-- Kill all connections and set to single user mode
USE	MASTER
GO
ALTER	DATABASE [DatabaseName] 
SET 	SINGLE_USER
WITH	ROLLBACK IMMEDIATE
GO

-- Do your operations

-- Set the database back in to multiple user mode
USE	MASTER
GO
ALTER	DATABASE [DatabaseName] 
SET 	MULTI_USER
GO

 
Kill All Connections Using The Kill Command
The following query will loop through all the open processes on the database and kill each one. Note that this may take a little bit of time to execute if there are long running transactions, it may take some time to roll them back.

USE	MASTER
GO

DECLARE	@Spid INT
DECLARE	@ExecSQL VARCHAR(255)

DECLARE	KillCursor CURSOR LOCAL STATIC READ_ONLY FORWARD_ONLY
FOR
SELECT	DISTINCT SPID
FROM	MASTER..SysProcesses
WHERE	DBID = DB_ID('DatabaseName')

OPEN	KillCursor

-- Grab the first SPID
FETCH	NEXT
FROM	KillCursor
INTO	@Spid

WHILE	@@FETCH_STATUS = 0
	BEGIN
		SET		@ExecSQL = 'KILL ' + CAST(@Spid AS VARCHAR(50))

		EXEC	(@ExecSQL)

		-- Pull the next SPID
        FETCH	NEXT 
		FROM	KillCursor 
		INTO	@Spid  
	END

CLOSE	KillCursor

DEALLOCATE	KillCursor

 
Reference: https://msdn.microsoft.com/en-us/library/bb522682(v=sql.105).aspx
https://msdn.microsoft.com/en-us/library/ms173730.aspx