using System;

using System.Collections.Generic;

using System.Linq;

using Microsoft.EntityFrameworkCore;

​

namespace EfExtensionsTest

{

    class Program

    {

        static void Main(string[] args)

        {

            using (var context = new BookStore())

            {

                var authors = new List<Author>

                {

                    new Author

                    {

                        FirstName ="Carson",

                        LastName ="Alexander",

                        BirthDate = DateTime.Parse("1985-09-01"),

                        Books = new List<Book>()

                        {

                            new Book { Title = "Introduction to Machine Learning"},

                            new Book { Title = "Advanced Topics on Machine Learning"},

                            new Book { Title = "Introduction to Computing"}

                        }

                    },

                    new Author

                    {

                        FirstName ="Meredith",

                        LastName ="Alonso",

                        BirthDate = DateTime.Parse("1970-09-01"),

                        Books = new List<Book>()

                        {

                            new Book { Title = "Introduction to Microeconomics"}

                        }

                    },

                    new Author

                    {

                        FirstName ="Arturo",

                        LastName ="Anand",

                        BirthDate = DateTime.Parse("1963-09-01"),

                        Books = new List<Book>()

                        {

                            new Book { Title = "Calculus I"},

                            new Book { Title = "Calculus II"}

                        }

                    }

                };

​

                //IncludeGraph allows you to INSERT/UPDATE/MERGE entities by including the child entities graph.

                context.BulkInsert(authors, options => options.IncludeGraph = true);

            }

​

            using (var context = new BookStore())

            {

                var list = context.Authors

                    .Include(a => a.Books)

                    .ToList();

​

                foreach (var author in list)

                {

                    Console.WriteLine(author.FirstName + " " + author.LastName);

​

                    foreach (var book in author.Books)

                    {

                        Console.WriteLine("\t" + book.Title);

                    }

                }

            }

        }

    }

​

    public class Author

    {

        public int AuthorId { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public DateTime BirthDate { get; set; }

        public List<Book> Books { get; set; }

    }

​

    public class Book

    {

        public int BookId { get; set; }

        public string Title { get; set; }

        public Author Author { get; set; }

    }

​

    public class BookStore : DbContext

    {

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

            optionsBuilder.UseInMemoryDatabase(databaseName: "BookStoreDb");

        }

​

        public DbSet<Author> Authors { get; set; }

        public DbSet<Book> Books { get; set; }

    }

}

​