CODEWITHSUNDEEP
c#entity-framework
nopskazoid
nopskazoid

Reputation: 181

Entity with 2 one-to-one properties to a common entity type

I have a couple of entity classes.

Parent:

public class Parent
{
    public Parent()
    {
    }

    public int ParentId { get; set; }

    public virtual Child Boy { get; set; }

    public virtual Child Girl { get; set; }
}

and Child:

public class Child
{
    public int ChildId { get; set; }

    public virtual Parent Parent { get; set; }
}

So, Parent has 2 one-to-one relationships with Child.

In OnModelCreating, I added the following:

modelBuilder.Entity<Parent>()
    .HasKey<int>(e => e.ParentId);

modelBuilder.Entity<Child>()
    .HasKey<int>(e => e.ChildId);

modelBuilder.Entity<Parent>()
    .HasOptional<Child>(p => p.Boy)
    .WithRequired(c => c.Parent)
    .WillCascadeOnDelete(true);

modelBuilder.Entity<Parent>()
    .HasOptional<Child>(p => p.Girl)
    .WithRequired(c => c.Parent)
    .WillCascadeOnDelete(true);

But I get an error when creating the database:

Schema specified is not valid. Errors: The relationship 'Example.Parent_Boy' >was not loaded because the type 'Example.Child' is not available.

How can I configure the model so that my entity can have 2 nullable, one-to-one relationships to the same entity type?

Upvotes: 0

Views: 45

Answers (1)

Scharly Ochoa
Scharly Ochoa

Reputation: 301

You can try this :

public Parent()
{
}

public int ParentId { get; set; }

public virtual List<Child> Children { get; set; }

public Child Boy{ get{ return Children.First(<BoyCondition>); } }
public Child Girl{ get{ return Children.First(<GirlCondition>); } }

Dont forget to ignore boy and girl propertys

modelBuilder.Entity<Parent>().Ignore(m => m.Boy);
modelBuilder.Entity<Parent>().Ignore(m => m.Girl);

Upvotes: 1

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