// 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();

        var context = new EntityContext();

        var totalPriceExample1 = context.Orders.Select("Price * Amount").Sum();

        Console.WriteLine("totalPriceExample1 = {0}", totalPriceExample1);

        var totalPriceExample2 = context.Orders.Sum("Price * Amount");

        Console.WriteLine("totalPriceExample2 = {0}", totalPriceExample2);

    }

    public static void GenerateData()

    {

        var orders = new List<Order>

        {

            new Order { Amount = 5, Price = 3 },

            new Order { Amount = 10, Price = 8 } 

        };

        using (var context = new EntityContext())

        {

            context.Orders.AddRange(orders);

            context.BulkSaveChanges();

        }

    }

    public class EntityContext : DbContext

    {

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

        {

        }

        public DbSet<Order> Orders { get; set; }

    }

    public class Order

    {

        public int Id { get; set; }

        public int Amount { get; set; }

        public double Price { get; set; }

    }

    public class Customer

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public string CompanyName { get; set; }

        public string City { get; set; }

        public string Phone { get; set; }

    }   

}