Entity Framework : Filter nested collection by value of its properties

Question

I have model as below

class MyClass()
{
   public int Id { get; set; }
   public List Items { get; set; }
}

class Item
{
     public int Id { get; s         


        

Answer 1

First of all correct your POCOs this way:

public class MyClass
{
   public int Id { get; set; }
   public virtual ICollection<Item> Items { get; set; }
}

public class Item
{
   public int Id { get; set; }
   public string Name { get; set; }

   public virtual MyClass MyClass {get;set}
   public int MyClassId {get;set}
}

Usage:

Presented query will return all MyClass instances, where at least one item's Name will satisfy condition:

var answer = db.MyClass.Where(c => c.Items.Any(item => item.Name == "Sam")).ToList();

This query will return all MyClass instances, where all item's Name will satisfy condition:

var answer = db.MyClass.Where(c => c.Items.All(item => item.Name == "Sam")).ToList();