Entity Framework Code First custom mapping using partial key

Question

Is it possible to do the following mapping with the Entity Framework Code First?

public class Parent
{
     [Key]
     public int ID {get; set;}
     public string statecode{get; set;}

     public virtual ICollection<Child> children{get; set;}
}

public class Child
{
    [Key, Column(Order = 0)]
    public string StateFromCode { get; set; }
    [Key, Column(Order = 1)]
    public string StateToCode { get; set; }
}

I would like to specify a relation in my dbcontext where children are lazy loaded into the Parent and Parent.statecode == Child.StateToCode. Note that StateToCode is part of the Child key and not the entire primary key. What should I specify in my DB context below to make this happen if possible at all?

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        modelBuilder.Entity<Parent>().HasMany(x=>x.children)..............

    }

Ladislav Mrnka · Accepted Answer · 2011-12-13 19:45:25Z

2

It is not possible - especially not with code first where relations must follow exactly same rules as specifying referential constraint in the database. So the only valid relation will require Parent's Id column in Child table and foreign constraint on this column

answered Dec 13, 2011 at 19:45

Ladislav Mrnka

365k60 gold badges666 silver badges673 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

lorenc Over a year ago

Thanks for you answer. I ended up populating children collection manually as 'p.children = dbcontext.Children.where(c=>c.StateToCode == p.statecode)' and changed the collection from ICollection<child> to [NotMapped] IEnumerable<child>.

Mike Cole Over a year ago

Is this still the case, or has the newer version made this functionality available?

Collectives™ on Stack Overflow

Entity Framework Code First custom mapping using partial key

1 Answer 1

2 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Related