db.Select<Author>(q => q.Earnings <= 50);

db.Select<Author>(q => q.Name.StartsWith("A"));

db.Select<User>(q => q.Where(x => x.LastName == "XYZ"));

db.Select<User>(q => q.LastName == "XYZ");

db.Select<Author>(...) //Author
db.Select<User>(...) //User