单项选择题
A.sp_dropdeviceB.sp_addumpdeviceC.sp_grantloginD.sp_addlogin
A.grant delete on students to helloB.revoke delete on students to helloC.revoke delete on students from helloD.deny delete on students to hello
A.每个角色有一定的权限B.是服务器权限的集合C.不能创建服务器角色D.能创建服务器角色