CODEWITHSUNDEEP
c#.netentity-frameworkentity-framework-6
hatcyl
hatcyl

Reputation: 2352

Entity Framework 6: Load related entities with null or blank foreign key

Parent has a collection of Child. Child has a Foreign Key to Parent (ParentID), but that foreign key might by null / blank. I want Entity Framework to always load Child with null / blank foreign key for all Parent.

public class Parent
{
    public string ID { get; set; }
    public virtual ICollection<Child> Children { get; set; } //Should load it's children AND children without foreign key.
}

public class Child
{
    public string ID { get; set; }
    public string ParentID { get; set; } //This can be null / blank.
}

Upvotes: 0

Views: 778

Answers (1)

joelmdev
joelmdev

Reputation: 11773

Without a ParentId, the child is what's known as an orphan. There's no way to link a child to a parent without a populated foreign key property.

If you're just looking to query the Children for records with a null or empty ParentId, do something like the following with your DbContext:

var orphans = myContext.Children.Where(child => String.IsNullOrEmpty(child.ParentId));

Upvotes: 2

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