How to extend table with a view in Entity framework

Question

I wanted to have a view to add a few extra proprieties and I tried the following:

Base table:

namespace Core.Model {

public class Item
{
    [Key]
    public int ItemId { get; set; }

    [Required]
    public ItemType Type { get; set; }

    [Required]
    [MaxLength(255)]
    public string Name { get; set; } 
    //...
}
}

extended view:

namespace Core.Model
{

    public class ItemExtended : Item
    {
        public int? CommentsCount { get; set; }
    }
}

Then in the Context I have:

public DbSet<QuiverItemExtended> ItemsExtended { get; set; }

modelBuilder.Entity<ItemExtended>()
    .ToTable("ItemsExtended")
    .HasKey(view => new { view.ItemId });

This works for querying but when I try to insert a normal Item I get this exception:

All objects in the EntitySet 'Context.Items' must have unique primary keys. However, an instance of type 'Core.Model.ItemExtended' and an instance of type 'Core.Model.Item' both have the same primary key value, 'EntitySet=Items;ItemId=1097'.

Any ideias how I can fix this?

thanks in advance

Similar issue http://stackoverflow.com/questions/3382285/entity-framework-and-inheritance-notsupportedexception — Steve Greene, Jul 16 '15 at 13:29

score 1 · Accepted Answer · answered Jul 16 '15 at 15:59

1

In this case I will solve this using a calculated column: http://www.davepaquette.com/archive/2012/09/23/calculated-columns-in-entity-framework-code-first-migrations.aspx

answered Jul 16 '15 at 15:59

RicardoSBA

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How to extend table with a view in Entity framework

1 Answers1