linq OrderBy property on object

Question

using EF4 is it possible to orderby a property on a property, i.e.

EntityA which has a Name property. Entity B has a few other properties and EntityA. I want to get a list of EntityB ordered by EntityA.Name

entityBList = _repo.Find<EntityB>() .OrderBy(x => x.EntityA.Name);

Yes it is. If you're having problems, you need to elaborate. — Tim Rogers, Apr 05 '13 at 11:03
added in my code, it returns a list of items, just unordered — newbie_86, Apr 05 '13 at 11:31
Have you tried this? What error do you get? What type does `Find` return? — greg84, Apr 05 '13 at 22:46
You are on the right track, but more detail is needed if you haven't figured it out already. — John C, Apr 17 '13 at 04:51

score 0 · Answer 1 · answered Apr 17 '13 at 05:29

Why doesn't this work? I know it's not using EF4, but the concept is the same.

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    namespace LinqOrderByReference
    {
        class Program
        {
            static void Main(string[] args)
            {
                EntityA[] entitiesA = {   new EntityA { Ordinal = 3, SecretCode = "xxx"}, 
                                          new EntityA { Ordinal = 2 ,SecretCode = "x"}, 
                                          new EntityA { Ordinal = 1 ,SecretCode = "x"} };
                EntityB[] entitiesB = {  new EntityB { Name = "C", EntityA = entitiesA[2] }, 
                                          new EntityB {Name = "B", EntityA = entitiesA[1] },
                                          new EntityB {Name = "A", EntityA = entitiesA[0] } };

                IEnumerable<EntityB> entitiesBList = entitiesB.OrderBy(x => x.EntityA.Ordinal);
                foreach (EntityB b in entitiesBList)
                {
                    Console.WriteLine("EntityB.Name: {0}, Ordinal {1}.", b.Name, b.EntityA.Ordinal);
                }
                Console.Read();
            }
        }

        public class EntityA
        {
            public int Ordinal { get; set; }
            public string SecretCode { get; set; }
        }

        public class EntityB
        {
            public string Name { get; set; }
            public EntityA EntityA { get; set; }
        }
    }

Output is:
EntityB.Name: C, Ordinal 1.
EntityB.Name: B, Ordinal 2.
EntityB.Name: A, Ordinal 3.

score 0 · Answer 2 · edited May 23 '17 at 11:50

0

Is the name property a simple string, or does it incorporate the First name and Last Name, and if so does it override the GetHashCode method? If so, you may want to look at this post What is the best algorithm for an overridden System.Object.GetHashCode?

edited May 23 '17 at 11:50

Community

1
1

answered Apr 17 '13 at 05:48

John C

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linq OrderBy property on object

2 Answers2