public ApplicationDbContext(DbContextOptions options) : base(options) { CategoriesTable.Add(new Category { Description = "Sci-fi" }); CategoriesTable.Add(new Category { Description = "History" }); AuthorizationLevelsTable.Add(new AuthorizationLevel { Name = "Admin" }); AuthorizationLevelsTable.Add(new AuthorizationLevel { Name = "Librarian" }); AuthorizationLevelsTable.Add(new AuthorizationLevel { Name = "User" }); SaveChanges(); var librarian = AuthorizationLevelsTable.Where(x => x.Name == "Librarian").FirstOrDefault(); var user = AuthorizationLevelsTable.Where(x => x.Name == "User").FirstOrDefault(); user.WhoHasTheLevel.Add(new Account { Name = "Alice" }); user.WhoHasTheLevel.Add(new Account { Name = "Bob" }); user.WhoHasTheLevel.Add(new Account { Name = "Cecilia" }); SaveChanges(); var servadac = new Book { Title = "Hector Servadac", WhenLent = DateTime.Now }; var alice = AccountsTable.Where(x => x.Name == "Alice").FirstOrDefault(); alice.BorrowedBooks.Add(servadac); SaveChanges(); var scifi = CategoriesTable.Where(x => x.Description == "Sci-fi").FirstOrDefault(); var now = DateTime.Now; var catEvent = new CategorizationEvent { When = now }; scifi.Events.Add(catEvent); servadac.Categorized.Add(catEvent); SaveChanges(); }