Given a list of items, each containing a subitem, get the subitems and remove duplicates

Question

Given a list of groupos, where each groupo has a single empresa and multiple groupos can have the same empresa, how do you get the empresas that contain any of the list's groupos?

I have this Model:

public class Grupo
{
    public int id { get; set; }
    public string descripccion { get; set; }
    [ForeignKey("Empresas")]
    public int empresa { get; set; }

    public virtual empresa Empresas { get; set; }
}


public class empresa
{    
    public int id { get; set; }
    public string descripcion { get; set; }

    public virtual ICollection<Grupo> Grupos { get; set; }
}

So this method gives me a List

private List<Grupo> VerEmpresas(int userId)
{    
    var lista = (from ga in db.GrupoAccesos
    join g in db.Grupos
        on ga.grupo equals g.id
    where ga.usuario == userId
    select g).ToList();
    return lista;
}

and now I want to use this method to show me the empresas that are related to grupo.

Below emp gives a bool, and instead I want all the empresas that are in my list of grupos.

List<Grupo> verEmpresa = VerEmpresas(1);

var emp = (from p in db.Empresas
           select p.Grupos).Contains(verEmpresa);       

ViewBag.empresa = new SelectList(emp, "id", "descripcion");

check this ! http://stackoverflow.com/questions/554649/how-to-bind-linq-data-to-dropdownlist — Gonzalo.-, Jul 19 '12 at 22:54
My problem is I have a list of grupos and what I want to know is given that list what empresas are relate to that grupos that are in the list — Diego_DX, Jul 19 '12 at 22:59

score 1 · Accepted Answer · answered Jul 20 '12 at 00:07

You can try getting the empresa ids from your Grupo list and using the foreign key relationship to get the empresas:

var empresaIds = verEmpresa.Select( v => v.empresa ).Distinct().ToList();
var emp = from p in db.Empresas
          where empresaIds.Contains( p.id )
          select p;

Bishnu Paudel · Answer 2 · 2012-07-19T23:56:24.113

0

In your code you are passing 'VerEmpresa' which is a list of Grupo. You should pass one object of Grupo from that list. Try using Any and All method on verEmpresa List. Try something like:

from p in db.Empresas
           where verEmpresa.Any(val => p.Contains(val))
           select p;

edited Jul 19 '12 at 23:56

answered Jul 19 '12 at 23:50

Bishnu Paudel

2,083
1
21
39

score 0 · Answer 3 · answered Jul 19 '12 at 23:57

0

If all you want is the empresas, try:

var emp = (from e in db.Empresas
           from g in db.Grupos
           where e.Grupos.Contains(g)
           select e);

answered Jul 19 '12 at 23:57

Derek Hunziker

12,996
4
57
105

Given a list of items, each containing a subitem, get the subitems and remove duplicates

3 Answers3