Search information in more than one table

Question

In my project I currently have 3 tables: Students, Occurrences and Users. In them I have the views and the controllers.

So far, so good. My relationships are: Allunos&occurrences(1,N) / Occurrences & users(N,1).

My problem is that in action Details, both of Occurrences and of Users, I can not show some relationship information. In the case of occurrences I cannot show the name of the student or the user (but in the Index, I can show these names), and in the case of users I cannot show the name of the student (which would have to be shown by the fact that it comes from the relationship of Alunos&occurrences).

Here’s my code that’s on action which shows all information, except those mentioned above:

Actionresult of Controller Occurrences

    public ActionResult Detalhes(long? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }

        Ocorrencia ocorrencia = db.Ocorrencias.Find(id);

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

Actionresult of Controller Users

    public ActionResult Detalhes(long? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        //Usuario usuario = db.Usuarios.Find(id);
        Usuario usuario = db.Usuarios.Include(o => o.Ocorrencias).AsNoTracking().FirstOrDefault(u => u.UsuarioID == id);

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

Could someone help me ? This is the case of a Join ?

Answer 1

Not use Find. Find brings only the requested registration, without the relationships between the other entities.

Change to FirstOrDefault, and use Include to load related data:

var ocorrencia = db.Ocorrencias
                 .Include(o => o.Aluno)
                 .Include(o => o.Usuario)
                 .FirstOrDefault(o => o.OcorrenciaID == id);

In the case of Usuario, don’t need to use AsNoTracking(). The rest is correct:

var usuario = db.Usuarios.Include(o => o.Ocorrencias).FirstOrDefault(u => u.UsuarioID == id);

Don’t forget to include the using System.Data.Entity; under the heading of Controllers.