// Dynamic LINQ - stef

​

// @nuget: System.Linq.Dynamic.Core

// @nuget: Z.EntityFramework.Classic

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Data.Entity;

using System.Linq.Dynamic.Core;

public class Program

{   

    public static void Main()

    {

        GenerateData();

​

        SelectMany();

        SelectMany_Dynamic();

    }

    private static void SelectMany()

    {

        var context = new EntityContext();

        var result = context.Xes.Where("Id > 10").SelectMany("x => x.items.Select(r => new (r.name, r.price))").ToDynamicArray();

        Console.WriteLine("All item-names : {0}", string.Join(", ", result));

    }

    private static void SelectMany_Dynamic()

    {

        var context = new EntityContext();

        var result = context.Xes.Where("Id > 10").SelectMany("items").Select("new (name, price)");

        FiddleHelper.WriteTable(result);

    }

    public static void GenerateData()

    {

        var xCollection = new List<X>();

        for(var j = 1; j <20;j++){

            var yCollection = new List<Y>();

            var xId =j; 

            for (var i = 0; i < 10; i++){

                yCollection.Add( new Y() 

                {

                    Id = i,

                    name = "Name as x.id="+ xId + " y.id=" + i,

                    price = i * 10

                });

            }

            xCollection.Add(new X()

            {

                Id = xId,

                items = yCollection

            });

        }

        Console.Write("X Ids: ");

        foreach(var item in xCollection){

            Console.Write(item.Id + ", ");

        }

        Console.WriteLine("");

​

        using (var context = new EntityContext())

        {

            context.Xes.AddRange(xCollection);

            context.BulkSaveChanges();

        }

    }

    public class EntityContext : DbContext

    {

        public EntityContext() : base(FiddleHelper.GetConnectionStringSqlServer())

        {

        }

        public DbSet<X> Xes { get; set; }

    }

    public class X

    {

        public int Id {set;get;}

        public ICollection<Y> items {set;get;}

    }

​

    public class Y

    {

        public int Id {set;get;}

        public string name {set;get;}

        public int price {set;get;}

        public int count {set;get;}

    }

​

}