How do you test for the existence of a user in SQL Server?

Question

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 sys

Answer 1

SSMS scripts it in the following way:

For SQL 2005/2008:

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

For SQL 2000:

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