Configure a many to one relationship in a Owned Entity in Entity Framework

Question

I have a class that is an entity in the DB and has a owned entity:

public class EntityOne
{
        public int Id { get; set; }
        public OwnedEntity OwnedEntity { get; set; }
}

I have the owned entity with a list with the type of another persisted entity:

public class OwnedEntity
{
        public int Id { get; set; }
        public List<EntityTwo> EntityTwo { get; set; }
}

And here is the EntityTwo:

public class EntityTwo
{
        public int Id { get; set; }
 
        // all other properties
}

I need to create the relationship between EntityOne and EntityTwo as a many to one, but the property navigation is in my owned entity. How can I do that?

I tried to create a property navigation of my owned entity like this:

public class EntityTwo
{
        public int Id { get; set; }

        public OwnedEntity OwnedEntity { get; set; }

        public int OwnedEntityId { get; set; }

        // all other properties
}

And the map:

builder.HasOne(prop => prop.OwnedEntity)
                .WithMany(prop => prop.EntityTwo)
                .HasForeignKey(prop => prop.OwnedEntityId);

But I got an error because ef tries to make my owned entity as a entity table.

Then, I tried to reference the parent entity:

public class EntityTwo
{
            public int Id { get; set; }
    
            public EntityOne EntityOne { get; set; }
    
            public int EntityOneId { get; set; }
    
            // all other properties
}

And mapping with inner properties:

builder.HasOne(prop => prop.EntityOne.OwnedEntity)
                .WithMany(prop => prop.EntityTwo)
                .HasForeignKey(prop => prop.EntityOne.OwnedEntityId);

But it didn't work and i got another ef error:

Error: The expression 'prop => prop.EntityOne.OwnedEntity' is not a valid member access expression. The expression should represent a simple property or field access: 't => t.MyProperty'. (Parameter 'memberAccessExpression')

So, is there any way to create this relationship?

Answer 1

For those who want to know how I solved it, I did it all inside the map configuration of the entity one, using the OwnsMany. First, I changed the one-to-many reference of EntityTwo to the OwnedEntity:

public class EntityTwo
{
            public int Id { get; set; }
    
            public OwnedEntity OwnedEntity { get; set; }
    
            public int OwnedEntityId { get; set; }
    
            // all other properties
}

Then, i made this map (builder of the EntityOne):

builder.OwnsOne(prop => prop.OwnedEntity, subBuilder =>
{
    // all map configurations of OwnedEntity

    subBuilder.OwnsMany(prop => prop.EntityTwo, ownedBuilder =>
    {
        ownedBuilder.HasOne(prop => prop.EntityTwo)
        .WithMany(prop => prop.OwnedEntity)
        .HasForeignKey(prop => prop.EntityTwoId);

        // all map configurations of EntityTwo
    }
}

That's it.