Question

I have a set of objects that map to my database and are populated correctly, however I have a case when I need to return a collection of objects based on a value of a grandchild object. The relationships between these objects are causing me issues to sucessfully create this linq query.

The objects are as follows:

public class Pet
{
    public int PetID { get; set; }
    public string Name { get; set; }

    public virtual int ToyID { get; set; }
    public virtual Toy Toy { get; set; }
}

public class Toy
{
    public int ToyID { get; set; }
    public string Name { get; set; }

    public virtual ICollection<Owner> Owners { get; set; }
    public virtual ICollection<Pet> Pets { get; set; }
}

public class Owner
{
    public int OwnerID {get; set;}
    public string Name {get; set;}

    public virtual ICollection<Toy> Toys { get; set; }
}

So basically its a 1 to many to many relationship.

I have a Collection of Pets and I would like restrict depending on the Owner object’s Name property.

Answer 1

What about this?

Pets.Where( p => p.Toy.Owners.Any(o => o.Name == "OwnerNameYourLookingFor") );

This will return an enumerable of Pets who have an OwnerNameYourLookingFor in their owner list.