namespace ExiaDemo.Metier
{
    public class UserRepository
    {
        public void rgLastNameUpper(User user) { }
        public void Inser(UserModel userModel) { }
        public void Delete(long id) { }
        public void rgFirstNameLower(User user) { }
        public void Update(UserModel userModel) { }
        public UserModel[] Select() {
            return new UserModel[] { };
        }
    }
}
namespace ExiaDemo.Metier
{
    public class UserModel
    {
        public long Id { get; set; }
        public string Login { get; set; }
        public string Password { get; set; }
        public string DisplayName { get; set; }
    }
}

namespace ExiaDemo.Database
{
    public class User
    {
        public long Id { get; set; }
        public string Login { get; set; }
        public string Password { get; set; }
        public string LastName { get; set; }
        public string FirstName { get; set; }
    }
}

namespace ExiaDemo.Database
{
    class Database : User
    {
        public Dictionary<string, User> Users = new Dictionary<string, User>();

        public void EditUser(User user) { }
        public void DeleteUser(long id) { }
        public void AddUser(User) { }
    }
}