How to get joined model column in other model?

Question

I'm working on simple ASP .NET MVC web app which using Entity Framework ( DB First ).

First functionality I'm working on is "Room Booking". For that, I have simple model:

public partial class Room
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Color { get; set; }
}

public partial class Reservation
{
    public int Id { get; set; }
    public int RoomId { get; set; }
    public int UserId { get; set; }
    public System.DateTime Start { get; set; }
    public System.DateTime Stop { get; set; }
    public string Description { get; set; }
}

public partial class User
{
    public int ID { get; set; }
    public string UserName { get; set; }
    public string FullName { get; set; }
}

I'm trying to create View like UserReservations, but I don't know how to get User.UserName and Room.Name in Reservation.

@foreach (var item in Model)
    {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Description)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.RoomId)
                //Here I want to have Room Name instead of RoomId.
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Start)
            </td>
            <td>
                @Html.DisplayFor(modelitem => item.Stop)
            </td>
            <td>

            </td>
        </tr>
    }

How to get Room.Name in Reservation model ? Do I have to modyify it ( I think there would be modyfications in the future, so model will be updated from database and all of those changes would be discarded).

You will need to create another model that contains properties that your join query is returning. — It's a trap, Apr 08 '19 at 07:36
if your models are configured correctly it should work like this: `reservationObject.Room.Name` and the correct way should be `public partial class Reservation{ public int RoomId { get; set; } public Room Room {get;set;}}` — Aarif, Apr 08 '19 at 08:24
@Aarif model comes from database. If there would be any changes on database, app model will change itself too. Am i right ? — fanarek, Apr 08 '19 at 08:45
I think in this case adding a property `public Room Room {get; set;}` doesn't change anything on schema level it just provides us some ease at the code level, the relationship remains the same, have you tried it though? — Aarif, Apr 08 '19 at 08:50
@Aarif Yes I have. It causes errors saying that `Room` is not part of the current context, which I'm currently working with. — fanarek, Apr 08 '19 at 09:06
@Aarif I've just created my own class which has properties of type `Room`,`User` and `Reservation` and it works. Thanks for advice. — fanarek, Apr 08 '19 at 09:16
@fanarek Please add your controller method code to the question. This is a very simple problem. — TanvirArjel, Apr 08 '19 at 09:33
You can view my answer here https://stackoverflow.com/questions/51044937/how-to-use-2-models-in-a-view/51045717#51045717 . You need to use MVVM pattern in this scenario — , Apr 08 '19 at 14:35

score 0 · Answer 1 · answered Apr 10 '19 at 09:51

you can add manual navigation property to Reservation (add navigation property User and Room in Reservation), after that you have a user, room property to call User.UserName and Room.Name from Reservation : [Entity Framework - Add Navigation Property Manually

score 0 · Answer 2 · answered Apr 10 '19 at 10:00

You can use foreign key in your database.If you use foreign key between Reservation->RoomId and Room->Id, your Reservation class is like above.

public partial class Reservation
{
    public int Id { get; set; }
    public int RoomId { get; set; }
    public int UserId { get; set; }
    public System.DateTime Start { get; set; }
    public System.DateTime Stop { get; set; }
    public string Description { get; set; }
    public virtual Room Room{ get; set; } //your foreign table
}

And so you can use Reservation.Room.Name in your view

How to get joined model column in other model?

2 Answers2