[sql] How to close existing connections to a DB

I want to close the existing connections to an MS SQL Server so that I can do a restore on that database programatically.

You can use Cursor like that:

USE master
GO

DECLARE @SQL AS VARCHAR(255)
DECLARE @SPID AS SMALLINT
DECLARE @Database AS VARCHAR(500)
SET @Database = 'AdventureWorks2016CTP3'

DECLARE Murderer CURSOR FOR
SELECT spid FROM sys.sysprocesses WHERE DB_NAME(dbid) = @Database

OPEN Murderer

FETCH NEXT FROM Murderer INTO @SPID
WHILE @@FETCH_STATUS = 0

    BEGIN
    SET @SQL = 'Kill ' + CAST(@SPID AS VARCHAR(10)) + ';'
    EXEC (@SQL)
    PRINT  ' Process ' + CAST(@SPID AS VARCHAR(10)) +' has been killed'
    FETCH NEXT FROM Murderer INTO @SPID
    END 

CLOSE Murderer
DEALLOCATE Murderer

I wrote about that in my blog here: http://www.pigeonsql.com/single-post/2016/12/13/Kill-all-connections-on-DB-by-Cursor

In more recent versions of SQL Server Management studio, you can now right click on a database and 'Take Database Offline'. This gives you the option to Drop All Active Connections to the database.

Perfect solution provided by Stev.org: http://www.stev.org/post/2011/03/01/MS-SQL-Kill-connections-by-host.aspx

IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[KillConnectionsHost]') AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[KillConnectionsHost]
GO


/****** Object:  StoredProcedure [dbo].[KillConnectionsHost]    Script Date: 10/26/2012 13:59:39 ******/

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE PROCEDURE [dbo].[KillConnectionsHost] @hostname varchar(MAX)
AS
    DECLARE @spid int
    DECLARE @sql varchar(MAX)

    DECLARE cur CURSOR FOR
        SELECT spid FROM sys.sysprocesses P
            JOIN sys.sysdatabases D ON (D.dbid = P.dbid)
            JOIN sys.sysusers U ON (P.uid = U.uid)
            WHERE hostname = @hostname AND hostname != ''
            AND P.spid != @@SPID

    OPEN cur

    FETCH NEXT FROM cur
        INTO @spid

    WHILE @@FETCH_STATUS = 0
    BEGIN
        PRINT CONVERT(varchar, @spid)

        SET @sql = 'KILL ' + RTRIM(@spid)
        PRINT @sql
        EXEC(@sql)

        FETCH NEXT FROM cur
            INTO @spid
    END

    CLOSE cur
    DEALLOCATE cur
GO

Short Answer:

You get "close existing connections to destination database" option only in "Databases context >> Restore Wizard" and NOT ON context of any particular database.

Long Answer:

Right Click on the Databases under your Server-Name as shown below:

and select the option: "Restore Database..." from it.

In the "Restore Database" wizard,

1. select one of your databases to restore
2. in the left vertical menu, click on "Options"

Here you can find the checkbox saying, "close existing connections to destination database"

Just check it, and you can proceed for the restore operation.

It automatically will resume all connections after completion of the Restore.

in restore wizard click "close existing connections to destination database"

in Detach Database wizard click "Drop connection" item.

Found it here: http://awesomesql.wordpress.com/2010/02/08/script-to-drop-all-connections-to-a-database/

DECLARE @dbname NVARCHAR(128)
SET @dbname = 'DB name here'
 -- db to drop connections 
DECLARE @processid INT 
SELECT  @processid = MIN(spid)
FROM    master.dbo.sysprocesses
WHERE   dbid = DB_ID(@dbname) 
WHILE @processid IS NOT NULL 
    BEGIN 
        EXEC ('KILL ' + @processid) 
        SELECT  @processid = MIN(spid)
        FROM    master.dbo.sysprocesses
        WHERE   dbid = DB_ID(@dbname) 
    END