Using query results with joined parameters without anonymous type

Question

Adapting from this C# MVC tutorial I'm using the following statement to return a specific user to the view

User user = db.Users.Find(id);

if (user == null){return HttpNotFound();}
return View(user);

The Users model has a foreign key to Auctions so the view can iterate over a list of auctions associated with this user.

Auctions has a field called buyerID which corresponds with User.ID so I want to display the buyers name by linking back to User.userName by way of the Auctions.buyerID.

I can do this in SQL statements and LINQ as well but I think there is a simpler way.

How can I use, User user = db.Users.Find(id); and join it to User from the foreign key of Auctions.buyerID?

This is kind of what I thought would work but I can't create a new parameter 'buyerName' when User doesn't have this.

IEnumerable<User> thisUser = from usr in db.Users
       join auct in db.Auctions on usr.ID equals auct.UserID
       join ur in db.Users on auct.buyerID equals ur.ID
       where usr.ID == id
       select new User
       {
           buyerName = ur.userName
       };

From other posts like this one I read about setting up a new class but that doesn't seem to stick to the DRY & KISS principles since now I need to have two classes that vary by one parameter located in different locations.

Is there a simpler way to join the table and get the strong typing without creating a new class?

So the result should display the buyers name instead of the buyers ID#

enter image description here

CodeKid · Accepted Answer · 2014-12-12 14:04:56Z

0

Since I wanted to avoid using anonymous type and I didn't want to create a new class I found a work around by passing a dictionary of user names to the view.

Controller

User user = db.Users.Find(id);

var dict = db.Users.Select(t => new { t.ID, t.userName })
           .ToDictionary(t => t.ID, t => t.userName);

ViewData["userDict"] = dict;

Now I just looked up the username based on the buyer ID

View

@{Dictionary<int, String> userList = ViewData["userDict"] as Dictionary<int, String>;}

@{
  if (item.buyerID.HasValue)
  {
    @Html.DisplayFor(modelItem => userList[item.buyerID.Value])
  }
}

answered Dec 12, 2014 at 14:04

CodeKid

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