首先，实体框架数据库，如何添加实体关联？

Question

I am not sure if the question is worded properly but here is what I am trying to do.

I am rewriting a VB.Net application where they were using linq-to-sql. They used an object that had many of another object in it:

[Table(Name = "dbo.ParentTable")]
public class ParentTable : LINQEntityBase, INotifyPropertyChanging, INotifyPropertyChanged
{
    //Stuff

    //This Guy 
    [Association(Name = "ParentTable_ParentTableProperties", Storage = "_ParentTableProperties", ThisKey = "WQI_Key", OtherKey = "WQI_Key")]
    public EntitySet<ParentTableProperty> ParentTableProperties { get; set; }

    //More stuff
}

When I generate my DB first model there isn't actually a relationship in the database so what I end up with is all of the properties in the table without the properties

public partial class ParentTable
{
    //stuff

    //I need to add the EntitySet or an IEnumerable<ParentTableProperty> here but this is a generated class....

}

Most of my very limited experience in ORMS is with Fluent NHibernate. I am not sure how to add the relationship in code (I cannot edit the tables for reasons I can't go into here).

A link to an article discussing this would be great. I am honestly not sure what I am trying to do is called (therefore my attempts at googleing were an epic failure).

Answer 1

Thanks to Robbin Cremers blog post I found a solution (I stress A SOLUTION because I don't know enough about this issue to say its the best one). Since Entity Framework uses partial classes to construct the objects from the database you can create your own customized object and add to the generated one:

 //**********************
 //Blah blah blah 
 //This is generated code
 //Blah blah blah
 //***********************

 public partial class ParentTable
 {
      //stuff
 }

and then in a new file (so that if you regenerate your model it does not get overwritten):

 public partial class ParentTable
 {
     public virtual DbSet<ParentTableProperty> Properties { get; set; }
 }

and now at compile time it will be compiled to look like one class.

 public class ParentTable
 {
     //stuff
     public virtual DbSet<ParentTableProperty> Properties { get; set; }
 }