// Entity Framework Classic

// Doc: https://entityframework-classic.net/csharp-eval-expression

​

// @nuget: Z.EntityFramework.Classic

// @nuget: Newtonsoft.Json

​

using System;

using System.Collections.Generic;

using System.Data.Entity;

using System.Linq;

using System.Linq.Expressions;  

using Newtonsoft.Json;

using Z.Expressions;

​

public class Program

{

    public static void Main()

    {

        GenerateData();

        var json = @"

[

    {

      'Type': 'Customer',

      'Properties': {

          'Code': 'Z0',

          'FirstName': 'ZZZ',

          'LastName': 'Projects'

      }

    },

    {

      'Type': 'Customer',

      'Properties': {

          'Code': 'Z1',

          'FirstName': 'Jonathan',

          'LastName': 'Magnan'

      }

    }

]

";

        dynamic list = JsonConvert.DeserializeObject(json);

        // register all types

        EvalManager.DefaultContext.RegisterAssembly(typeof(Program).Assembly);

​

        using (var context = new EntityContext())

        {   

            var listToMerge = new List<object>();

            foreach(var item in list)

            {

                var obj = Eval.Execute("new " + item.Type + "()");

                listToMerge.Add(obj);

​

                foreach(var property in item.Properties)

                {

                    Eval.Execute(property.Name + " = '" + property.Value + "'", obj);

                }

            }

            FiddleHelper.WriteTable("1 - Before Merge", context.Customers.AsNoTracking());

            if(listToMerge.Count > 0 && listToMerge[0] is Customer)

            {

                context.BulkMerge(listToMerge.Cast<Customer>(), options => options.ColumnPrimaryKeyExpression = x => x.Code);

            }

            FiddleHelper.WriteTable("2 - After Merge", context.Customers.AsNoTracking());

        }

    }

​

    public static void GenerateData()

    {

        using (var context = new EntityContext())

        {

            context.Customers.Add(new Customer() { Code = "Z0", FirstName = "Before_FirstName_0", LastName = "Before_LastName_0"});

            context.Customers.Add(new Customer() { Code = "Z1", FirstName = "Before_FirstName_1", LastName = "Before_LastName_1"});         

            context.SaveChanges();  

        }

    }

    public static string GetTitle(Expression expression)

    {

        return expression.ToString().Substring(expression.ToString().IndexOf(".Where"));

    }

​

    public class EntityContext : DbContext

    {       

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

        {       

        }

​

        public DbSet<Customer> Customers { get; set; }

    }

    public class Customer

    {

        public int CustomerID { get; set; }

        public string Code { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

    }

}