SQL Server 2008 R2：按条件删除数据库

Question

Now, what I am trying here is DROPPING the database from my SQL Server on the basis of any condition (Inside a IF block), eg. If database exists, delete and recreate it.

I am using following code:

IF EXISTS (SELECT 1 FROM sys.databases db with(nolock) WHERE db.name = 'practice')
BEGIN
    USE master
    DROP DATABASE practice
END

This code keeps on executing for couple of minutes and then replies with an error saying

Msg 3702, Level 16, State 4, Line 1
Cannot drop database "practice" because it is currently in use.

Then for another attempt I used a GO statement within my code to separate the execution flow, with following code (NOTE this has create database statement as well):

IF EXISTS (SELECT 1 FROM sys.databases db with(nolock) WHERE db.name = 'practice')
BEGIN
    USE master
    GO

    DROP DATABASE practice
    GO

    CREATE DATABASE practice
END

Now it throws this error:

Msg 102, Level 15, State 1, Line 3
Incorrect syntax near 'master'.
Msg 3702, Level 16, State 4, Line 1
Cannot drop database "practice" because it is currently in use.
Msg 102, Level 15, State 1, Line 2
Incorrect syntax near 'END'

I don't know if I am missing something, or is there any workaround that needs to be done.

Also, I would be interested in better alternates to serve this purpose, if any.

I don't know if this is even feasible.

Regards, Shanks

Answer 1

As the error message suggests,database is in use.You can drop databases forcefully using below script

 if exists(select * from sys.sysdatabases where name ='test')
    begin
    use master;

    alter database test
    set single_user with rollback immediate;

    drop database test;

    end

Answer 2

You can also do an

sp_who2 

to see who or what is connected to that DB. You can then use a

KILL SPID# (i.e. "KILL 54") 

to force that connection to close. This is dangerous if you are in production but if you are dropping and recreating the DB anyways...

This is a little more surgical than what @TheGameiswar suggests but is very similar.

Answer 3

For the purpose of practice can use following code:

EXEC msdb.dbo.sp_delete_database_backuphistory @database_name = N'practice'
GO
USE [master]
GO
ALTER DATABASE [practice] SET  SINGLE_USER WITH ROLLBACK IMMEDIATE
GO
DROP DATABASE [practice]
GO

now you can create your new DB.