Question

I need to write a function to delete the login in the database if it does not have any users to map to using SQL Server Management Objects (SMO). How can I achieve this ?

Just like to add that when using the login.EnumDatabaseMappings(),when there are no users mappped to the login , will return null.So you can not use something like login.EnumDatabaseMappings().Length rather you should use

    mylogin = server.Logins(loginName)
    If Not mylogin Is Nothing Then
        If Not mylogin.EnumDatabaseMappings() Is Nothing Then
            mylogin.Drop()
        End If
    End If

Answer 1

How about this:

Server server = new Server("your server name");

foreach (Login login in server.Logins)
{
    DatabaseMapping[] mappings = login.EnumDatabaseMappings();
}

Should work and give you what you’re looking for.