如何测试SQL Server中是否存在用户？

I'd like to drop a user in a SQL Server script but I'll need to test for existence first or I'll get script errors. When dropping tables or stored procs, I check the sysobjects table like so:

我想在SQL Server脚本中删除用户，但我需要先测试存在，否则我会收到脚本错误。当删除表或存储过程时，我检查sysobjects表，如下所示：

IF EXISTS (
    SELECT * 
    FROM   sysobjects 
    WHERE  id = object_id(N'[dbo].[up_SetMedOptions]') 
    AND    OBJECTPROPERTY(id, N'IsProcedure') = 1
)
Drop Procedure up_SetMedOptions;
GO

What is the corollary for checking for a user? Note that I am NOT asking about a database login to the server! The question pertains to a User in a specific database.

检查用户的必然结果是什么？请注意，我不是要求数据库登录到服务器！该问题与特定数据库中的用户有关。

3 个解决方案

#1

SSMS scripts it in the following way:

SSMS以下列方式编写脚本：

For SQL 2005/2008:

对于SQL 2005/2008：

IF  EXISTS (SELECT * FROM sys.database_principals WHERE name = N'username')
DROP USER [username]

For SQL 2000:

对于SQL 2000：

IF  EXISTS (SELECT * FROM dbo.sysusers WHERE name = N'username')
EXEC dbo.sp_revokedbaccess N'username'

#2

In SQL 2005:

在SQL 2005中：

select * from sys.sysusers

In SQL 2000:

在SQL 2000中：

select * from sysusers

#3

-1

The code below worked for me.

下面的代码对我有用。

IF EXISTS (SELECT * FROM sys.syslogins WHERE name = N'MyUserName') 
DROP LOGIN [MyUserName]

#1