/// <summary> /// 9. /// Create a method that places a new order in the Northwind database. /// The order should contain several order items. /// Use transaction to ensure the data consistency. /// </summary> private static void AddOrder() { var databaseConnection = new NorthwindEntities(); using (databaseConnection) { using (var dbContextTransaction = databaseConnection.Database.BeginTransaction()) { try { var newOrder = new Order() { CustomerID = "BOTTM", EmployeeID = 5, OrderDate = DateTime.Now }; newOrder.Order_Details.Add(new Order_Detail { ProductID = 11, UnitPrice = 14.00m, Quantity = 12, Discount = 0 }); newOrder.Order_Details.Add(new Order_Detail { ProductID = 42, UnitPrice = 9.80m, Quantity = 5, Discount = 0 }); newOrder.Order_Details.Add(new Order_Detail { ProductID = 72, UnitPrice = 34.50m, Quantity = 7, Discount = 0 }); databaseConnection.Orders.Add(newOrder); databaseConnection.SaveChanges(); dbContextTransaction.Commit(); } catch (Exception) { dbContextTransaction.Rollback(); } } } }
public static void UpdateCustomer(string customerToEditID, string newName) { var databaseConnection = new NorthwindEntities(); using (databaseConnection) { var customer = databaseConnection.Customers.FirstOrDefault(c => c.CustomerID == customerToEditID); customer.ContactName = newName; databaseConnection.SaveChanges(); } }
public static void DeleteCustomer(string customerToEditID) { var databaseConnection = new NorthwindEntities(); using (databaseConnection) { var customer = databaseConnection.Customers.FirstOrDefault(c => c.CustomerID == customerToEditID); if (customer != null) { databaseConnection.Customers.Remove(customer); databaseConnection.SaveChanges(); } } }
public static void InsertCustomer(string customerID, string companyName, string contactName, string contactTitle) { var databaseConnection = new NorthwindEntities(); var newCustomer = new Customer { CustomerID = customerID, CompanyName = companyName, ContactName = contactName, ContactTitle = contactTitle }; using (databaseConnection) { databaseConnection.Customers.Add(newCustomer); databaseConnection.SaveChanges(); } }