public string Login(Login login)
 {
     throw new NotImplementedException();
 }
       public LoginBack Login(Login login)
        {
            Console.WriteLine(login.UserName + "Login");                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
            LoginBack loginBack = new LoginBack();
            UserTable user = db.UserTables.SingleOrDefault(c => c.UserName == login.UserName&&c.Password==login.Passwrod);
            AcquirerTable acquirer = db.AcquirerTables.SingleOrDefault(c => c.UserName == login.UserName && c.PassWord == login.Passwrod);
          //  MerChantTable merchant = db.MerChantTables.SingleOrDefault(c => c.UserName == login.UserName && c.PassWord == login.Passwrod);
           if (user != null)
            {
                loginBack.Message = "OK";
                loginBack.UserId = user.Id;
                loginBack.UserType = 0;
                Console.WriteLine(login.UserName + "Login Success");
                return loginBack;
            }
            if (acquirer != null)
            {
                loginBack.Message = "OK";
                loginBack.UserId = acquirer.Id;
                loginBack.UserType = 1;
                Console.WriteLine(login.UserName + "Login Success");
                return loginBack;
            }
            //if (merchant != null)
            //{
            //    loginBack.Message = "OK";
            //    loginBack.UserId = merchant.Id;
            //    loginBack.UserType = 2;
            //    return loginBack;
            //}

            loginBack.Message = "Error";
            loginBack.UserId = -1;
            loginBack.UserType = -1;
            return loginBack;
        }