SSMS 按照以下方式编写脚本:

SSMS scripts it in the following way:

对于 SQL 2005/2008:

For SQL 2005/2008:

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

对于 SQL 2000:

For SQL 2000:

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