c# - code first get values from foreign key constraint -

i've started sample project code first , null value entity has foreign key constraint.

my model:

public class customeritem {      [key]      public int id { get; set; }      public int name{get;set;}      public virtual ienumerable<orderitem> order { get; set; } }  public class orderitem {     [key]     public int id { get; set; }      [foreignkey("customeritem")]     public int customerid { get; set; }     public virtual customeritem customeritem { get; set; } } 

dataaccess linq query values:

public ienumerable<customeritem> getordersfromcustomeritem(int id) {     return (from c in this.dax.customer            c.id.compareto(id) == 0            select c).asenumerable().tolist(); } 

this query return null orders think there's mistake in query. how can wire entity foreign key table?

thanks

updated query customers (and orders) this:

public ienumerable<customeritem> getallcustomers() {     return (from c in this.dax.customer             select new              {                 //properties                 orderitem = c.orderitem             }).asenumerable.tolist().select(s => new customeritem             {                //properties                orderitem = s.orderitem, //here got exception wrote in comment             }).tolist(); } 

change:

public virtual ienumerable<orderitem> order { get; set; } 

to:

public virtual icollection<orderitem> order { get; set; } 

since ienumerable<> exposes read-only methods, entity framework ignoring it. property must of writeable collection type in order map database.

it quite common though, expose ienumerable property, , have it's getter returning backing-field ilist/icollection.