public static void Initialize(StorageContext storageContext) { if (storageContext == null) { throw new ArgumentNullException(nameof(storageContext)); } if (!storageContext.Products.Any()) { storageContext.Products.AddRange( new Product() { Name = "Doll", Price = 500 }, new Product() { Name = "Lego", Price = 1000 }, new Product() { Name = "Tesla Model S Plaid+", Price = 157490 }, new Product() { Name = "Tesla Model 3 Long Range", Price = 58990 }, new Product() { Name = "Tesla Model X Plaid", Price = 141990 }, new Product() { Name = "Tesla Model Y Long Range", Price = 62490 } ); storageContext.SaveChanges(); } var products = new List <Product>(); products.AddRange(storageContext.Products.ToList()); if (!storageContext.Categories.Any()) { storageContext.Categories.AddRange( new Category() { Name = "Cars", Products = products }, new Category() { Name = "Toys" } ); storageContext.SaveChanges(); } var product = new Product(); product = storageContext.Products.Select(p => p).Where(p => p.Id == 1).FirstOrDefault(); if (!storageContext.Orders.Any()) { // storageContext.Orders.AddRange( // new Order() // { // // User = "******", // Address = "Nadvirna", // Phone = "380963235503", // OrderDateTime = DateTime.Now, // Products = product // } // ); storageContext.SaveChanges(); } }