public static async Task Seed(IApplicationBuilder applicationBuilder) { LibraryDbContext context = applicationBuilder.ApplicationServices.GetRequiredService <LibraryDbContext>(); UserManager <IdentityUser> userManager = applicationBuilder.ApplicationServices.GetRequiredService <UserManager <IdentityUser> >(); // Add Lender var user = new IdentityUser("Apu"); await userManager.CreateAsync(user, "Apu"); // Add Customers var justin = new Customer { Name = "Fuad Farhad" }; var willie = new Customer { Name = "Sadman Radib" }; var leoma = new Customer { Name = "Siam Hossain" }; context.Customers.Add(justin); context.Customers.Add(willie); context.Customers.Add(leoma); // Add Author var authorDeMarco = new Author { Name = "M J DeMarco", Books = new List <Book>() { new Book { Title = "The Millionaire Fastlane" }, new Book { Title = "Unscripted" } } }; var authorCardone = new Author { Name = "Grant Cardone", Books = new List <Book>() { new Book { Title = "The 10X Rule" }, new Book { Title = "If You're Not First, You're Last" }, new Book { Title = "Sell To Survive" } } }; context.Authors.Add(authorDeMarco); context.Authors.Add(authorCardone); context.SaveChanges(); }