如何编写SQL查询以找出哪些登录已被授予Sql Server 2005中的哪些权限？

I'm responsible for some test database servers. Historically, too many other poeple have access to them. They run on SQL Server 2005. I've been writing queries and wrapping them in scripts so I can run a regular audit of rights. Finding out which users had Administrator rights on the server itself was fine, as was finding out who had the 'sysadmin' role on their login - it was a single line query for the latter.I'm responsible for some test database servers.