方法一

-- 1. 设置数据库为单用户模式（可选）
ALTER DATABASE dbname SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
GO
-- 2. 删除数据库
DROP DATABASE dbname;
GO

方法二

-----杀进程---
USE master;
GO
DECLARE @SQL VARCHAR(MAX);
SET @SQL=''
SELECT @SQL=@SQL+'; KILL '+RTRIM(SPID)   
FROM master..sysprocesses
WHERE dbid=DB_ID('dbname');

EXEC(@SQL);
ALTER DATABASE [dbname] SET MULTI_USER;


----查询数据库所有进程---------
SELECT * FROM sys.sysprocesses WHERE dbid = DB_ID('dbname')

---删除数据库---
ALTER DATABASE dbname SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
GO

DROP DATABASE dbname;
GO