public async Task <ActionResult> Delete(int id)
{
try
{
// Searching for record in the Dish table (if its not found an exception is thrown)
var response = await _repository.GetById(id);
var order_list = await _orderDishRepository.getOrderList(id);
foreach (Order order in order_list) // Orders that contain the dish to be deleted
{
// If the removed dish is the only one contained in an order, then delete the order as well
if (await _orderDishRepository.getNumberOfDishes(order.Order_ID) == 1)
{
// It is the last dish contained in this order
// Remove the Order, but check if it is the last order in the transaction
if (await _orderRepository.numOrderByTransaction(order.Transaction_ID) == 1) // If the order is the only one in the transaction
{
// Removinng both the order and transaction
await _orderRepository.DeleteById(order.Order_ID);
await _transactionRepository.DeleteById(order.Transaction_ID);
// NOTE Elements in the Order_Dish table will also be deleted (cascading) which is what we want.
}
else // Transaction contains more than 1 orders still
{
await _orderRepository.DeleteById(order.Order_ID);
// Updating the transaction
await _transactionRepository.updateAmount(order.Transaction_ID, await _transactionRepository.getAmount(order.Transaction_ID) - response.Price);
// NOTE Elemets in the Order_Dish table will also be deleted (cascading) which is what we want.
}
}
else
{
// If it is not the last dish we do the following
// Update the transaction related to the order (which the dish is in)
await _transactionRepository.updateAmount(order.Transaction_ID, await _transactionRepository.getAmount(order.Transaction_ID) - response.Price);
}
}
// After validating the database constraints, delete the dish
await _repository.DeleteById(id);
string format = "Dish record with key={0} and related records deleted succesfully due to database constraints\n";
return(Ok(string.Format(format, id)));
}
catch (Npgsql.PostgresException ex)
{
// Postgres threw an exceptions
return(BadRequest(ex.Message.ToString()));
}
catch
{
// Unknown errors
return(BadRequest("Error: Dish record could not be deleted\n"));
}
}
public async Task <List <Order> > Get(int dish_id)
{
// Get all orders containing the specified dish
return(await _repository.getOrderList(dish_id));
}