// Multi-purpsoe public void CustomerPlaceOneOrder(COrder order, CStore store, double totalCost) { using var context = new Project0databaseContext(_contextOptions); // update order var newOrder = new Orderr { Orderid = order.Orderid, Storeloc = order.StoreLocation.Storeloc, Customerid = order.Customer.Customerid, Orderedtime = DateTime.Now, Totalcost = totalCost }; context.Orderrs.Add(newOrder); context.SaveChanges(); // update Orderproduct foreach (var product in order.ProductList) { var newOP = new Orderproduct { Orderid = order.Orderid, Productid = product.UniqueID, Quantity = product.Quantity }; context.Orderproducts.Add(newOP); } context.SaveChanges(); var dbStore = context.Stores.Include(x => x.Inventories) .FirstOrDefault(x => x.Storeloc == order.StoreLocation.Storeloc); // if (dbStore == null) return null; // update inventory quantity foreach (var product in order.ProductList) { foreach (var dbProd in dbStore.Inventories) { if (product.UniqueID == dbProd.Productid) { dbProd.Quantity = store.Inventory[product.UniqueID].Quantity; } } } context.SaveChanges(); }