杀他，用火杀他。

USE master
go

DECLARE @dbname sysname
SET @dbname = 'yourdbname'

DECLARE @spid int
SELECT @spid = min(spid) from master.dbo.sysprocesses where dbid = db_id(@dbname)
WHILE @spid IS NOT NULL
BEGIN
EXECUTE ('KILL ' + @spid)
SELECT @spid = min(spid) from master.dbo.sysprocesses where dbid = db_id(@dbname) AND spid > @spid
END

Adam建议的方法不起作用的原因是，在循环活动连接的时间内，可以建立新的连接，而您将错过这些连接。你可以使用下面的方法，它没有这个缺点:

-- set your current connection to use master otherwise you might get an error

use master
ALTER DATABASE YourDatabase SET SINGLE_USER WITH ROLLBACK IMMEDIATE 

--do you stuff here 

ALTER DATABASE YourDatabase SET MULTI_USER

使用SQL Management Studio Express:

在对象资源管理器树中，在管理下向下钻到“活动监视器”(如果你在那里找不到它，那么右键单击数据库服务器并选择“活动监视器”)。打开活动监视器，您可以查看所有进程信息。您应该能够找到您感兴趣的数据库的锁并关闭这些锁，这也将关闭连接。

您应该能够在此之后重命名。

右键单击数据库名称，单击属性进入属性窗口，打开选项选项卡，将“限制访问”属性从多用户更改为单用户。当你点击OK按钮时，它会提示你关闭所有打开的连接，选择“是”，你就可以将数据库重命名为....

脚本来完成这个任务，用数据库替换'DB_NAME'来杀死所有连接到:

USE master
GO

SET NOCOUNT ON
DECLARE @DBName varchar(50)
DECLARE @spidstr varchar(8000)
DECLARE @ConnKilled smallint
SET @ConnKilled=0
SET @spidstr = ''

Set @DBName = 'DB_NAME'
IF db_id(@DBName) < 4
BEGIN
PRINT 'Connections to system databases cannot be killed'
RETURN
END
SELECT @spidstr=coalesce(@spidstr,',' )+'kill '+convert(varchar, spid)+ '; '
FROM master..sysprocesses WHERE dbid=db_id(@DBName)

IF LEN(@spidstr) > 0
BEGIN
EXEC(@spidstr)
SELECT @ConnKilled = COUNT(1)
FROM master..sysprocesses WHERE dbid=db_id(@DBName)
END

下面是如何在MS SQL Server Management Studio 2008(可能也适用于其他版本)中可靠地执行这类事情:

In the Object Explorer Tree, right click the root database server (with the green arrow), then click activity monitor. Open the processes tab in the activity monitor, select the 'databases' drop down menu, and filter by the database you want. Right click the DB in Object Explorer and start a 'Tasks -> Take Offline' task. Leave this running in the background while you... Safely shut down whatever you can. Kill all remaining processes from the process tab. Bring the DB back online. Rename the DB. Bring your service back online and point it to the new DB.