EFCoreCosmosProviderTest.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.EntityFrameworkCore;

namespace TestCosmos
{
    // Console App (.NET Core)
    //<ItemGroup>
    //<PackageReference Include = "Microsoft.EntityFrameworkCore.Cosmos" Version="2.2.0-preview3-35497" />
    //<PackageReference Include = "Microsoft.EntityFrameworkCore.Tools" Version="2.2.4"/>
    //</ItemGroup>
    public class Book
    {
        public string ISBN { get; set; }
        public string Title { get; set; }
        public string Author { get; set; }
        public string Language { get; set; }
        public int Pages { get; set; }
        public virtual Publisher Publisher { get; set; }
    }

    public class Publisher
    {
        public string Id { get; set; }
        public string Name { get; set; }
        public virtual ICollection<Book> Books { get; set; }
    }

    public class LibraryContext : DbContext
    {
        public DbSet<Book> Book { get; set; }

        public DbSet<Publisher> Publisher { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            string endPoint = "https://localhost:8081";
            string authKey = "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==";
            string dbName = "LibraryDb";
            optionsBuilder.UseCosmos(endPoint, authKey, dbName);
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<Publisher>(entity =>
            {
                entity.HasKey(e => e.Id);
                entity.Property(e => e.Name).IsRequired();
            });

            modelBuilder.Entity<Book>(entity =>
            {
                entity.HasKey(e => e.ISBN);
                entity.Property(e => e.Title).IsRequired();
                entity.HasOne(d => d.Publisher)
                    .WithMany(p => p.Books);
            });
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            InsertData();
            PrintData();
        }

        private static void InsertData()
        {
            using (var context = new LibraryContext())
            {
                // Creates the database if not exists
                context.Database.EnsureCreated();

                // Adds a publisher
                var publisher = new Publisher
                {
                    Id = Guid.NewGuid().ToString(),
                    Name = "Mariner Books"
                };
                context.Publisher.Add(publisher);

                // Adds some books
                context.Book.Add(new Book
                {
                    ISBN = "978-0544003415",
                    Title = "The Lord of the Rings",
                    Author = "J.R.R. Tolkien",
                    Language = "English",
                    Pages = 1216,
                    Publisher = publisher
                });
                context.Book.Add(new Book
                {
                    ISBN = "978-0547247762",
                    Title = "The Sealed Letter",
                    Author = "Emma Donoghue",
                    Language = "English",
                    Pages = 416,
                    Publisher = publisher
                });

                // Saves changes
                context.SaveChanges();
            }
        }

        private static void PrintData()
        {
            // Gets and prints all books in database
            using (var context = new LibraryContext())
            {
                var books = context.Book
                    .Include(p => p.Publisher);
                foreach (var book in books)
                {
                    var data = new StringBuilder();
                    data.AppendLine($"ISBN: {book.ISBN}");
                    data.AppendLine($"Title: {book.Title}");
                    data.AppendLine($"Publisher: {book.Publisher.Name}");
                    Console.WriteLine(data.ToString());
                }
            }
        }
    }
}