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ASP.NET Core - How to update existing record and insert a new one at the same time using Entity Framework

In ASP.NET Core-6 Web API Entity Framework, I want the application to perform update and insert on the same model in the database at the same time.
I have this code:
public async Task<Response<string>> CreateIdentiticationAsync(CreateIdentiticationDto model)
{
var response = new Response<string>();
using (var transaction = new TransactionScope(TransactionScopeAsyncFlowOption.Enabled))
{
try
{
var identification = _mapper.Map<Identification>(model);
var existingIdentifications = await _dbContext.Identifications.Where(e => e.IsModified == false).ToListAsync();
foreach (var existingIdentification in existingIdentifications)
{
if (existingIdentification != null)
{
existingIdentification.IsModified = true;
_unitOfWork.UserIdentifications.Update(identification);
await _unitOfWork.Save();
}
}
Identification.IsModified = false;
Identification.Type = model.Type;
Identification.Name = model.Name;
await _unitOfWork.UserIdentifications.InsertAsync(identification);
await _unitOfWork.Save();
response.StatusCode = (int)HttpStatusCode.Created;
response.Successful = true;
response.Message = "Created Successfully!";
transaction.Complete();
return response;
}
catch (Exception ex)
{
transaction.Dispose();
response.Message = "An error occured";
response.Successful = false;
response.StatusCode = (int)HttpStatusCode.BadRequest;
return response;
}
}
}
When user wants to insert a new record, I want the application to first check the model, if no record exists it should just insert the new record.
But if it exists, it should update all the IsModified to true, and then go ahead and also insert a new record.
However, when no record exists, I was able to insert new record.
But where I have issue is that when it wants to update and insert new record, I got this error:
Violation of PRIMARY KEY constraint 'PK_identifications'. Cannot insert duplicate key in object 'dbo.identifications'. The duplicate key value is (81fe9b8d-2d9c-4d49-8f92-22afe043e327).
Note: Id is Guid and autgenerated
How do I resolve this?
Thanks

Many things to consider here, in modern EF, I would not use a unitOfWork also a transaction is not needed unless very specific cases, you should also validate the ID from your incoming model value is null since ID is supposed to be autogenerated (most likely this is the source of your error). Since I don't know the name of your PK field, I will not introduce such validation in my proposed code.
One last recommendation, avoid this code on your controller, it breaks Single Responsibility Principle. Create a layer where you perform your business tasks and call this layer from your controller.
Here is a simplified proposed code which should work, don't forget to ensure the value in the model ID is coming as null.
public async Task<Response<string>> CreateIdentiticationAsync(CreateIdentiticationDto model)
{
var response = new Response<string>();
try
{
var identification = _mapper.Map<Identification>(model);
var existingIdentifications = await _dbContext.Identifications.Where(e => e.IsModified == false).ToListAsync();
foreach (var existingIdentification in existingIdentifications)
{
existingIdentification.IsModified = true;
}
Identification.IsModified = false;
// If you already mapped this in line 6 why map those two fields again manually?
// Identification.Type = model.Type;
// Identification.Name = model.Name;
_dbContext.UpdateRange(existingIdentifications);
_dbContext.Add(identification);
await _dbContext.SaveChangesAsync();
response.StatusCode = (int)HttpStatusCode.Created;
response.Successful = true;
response.Message = "Created Successfully!";
return response;
}
catch (Exception ex)
{
transaction.Dispose();
response.Message = "An error occured";
response.Successful = false;
response.StatusCode = (int)HttpStatusCode.BadRequest;
return response;
}
}

public IActionResult Update(int? id,UpdateEmployeeVM employeeVM)
{
ViewBag.Positions = new SelectList(_context.Positions, nameof(Position.Id), nameof(Position.Name));
Employee existed=_context.Employees.Find(id);
if(existed==null) { NotFound();}
if (!_context.Positions.Any(p => p.Id == employeeVM.PositionId)) ModelState.AddModelError("PoitionId", "Choose Id right");
if (!ModelState.IsValid)
{
ViewBag.Positions = new SelectList(_context.Positions, nameof(Position.Id), nameof(Position.Name));
return View();
}
if (employeeVM.Image!=null)
{
string result = employeeVM.Image.CheckValidate("image/", 300);
if (result.Length > 0)
{
ViewBag.Positions=new SelectList(_context.Positions,nameof(Position.Id),nameof(Position.Name));
ModelState.AddModelError("Image", result);
}
existed.ImageUrl.DeleteFile(_env.WebRootPath, "assets/img");
existed.ImageUrl = employeeVM.Image.SaveFile(Path.Combine(_env.WebRootPath, "assets", "img"));
return View();
}
existed.PositionId=employeeVM.PositionId;
existed.FullName=employeeVM.FullName;
existed.ImageUrl = employeeVM.Image.SaveFile(Path.Combine(_env.WebRootPath, "assets", "img"));
_context.SaveChanges();
return RedirectToAction(nameof(Index));
}

public async Task<IActionResult> Create(CreateEmployeeVM employeeVM)
{
if (!_context.Positions.Any(p => p.Id == employeeVM.PositionId)) ModelState.AddModelError("PositionId", "bele bir position yoxdu");
if (!ModelState.IsValid)
{
ViewBag.Positions = new SelectList(_context.Positions, nameof(Position.Id), nameof(Position.Name));
return View();
}
string result = employeeVM.Image.CheckValidate(500,"image/");
if (result.Length > 0)
{
ViewBag.Positions = new SelectList(_context.Positions, nameof(Position.Id), nameof(Position.Name));
ModelState.AddModelError("Image", result);
return View();
}
Employee employee = new Employee
{
Name = employeeVM.Name,
Surname = employeeVM.Surname,
PositionId = employeeVM.PositionId,
FacebookUrl = employeeVM.FacebookUrl,
InstagramUrl = employeeVM.InstagramUrl,
TwitterUrl = employeeVM.TwitterUrl,
Salary = employeeVM.Salary,
ImageUrl = employeeVM.Image.SaveFile(Path.Combine(_env.WebRootPath, "assets", "img"))
};
await _context.Employees.AddAsync(employee);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}

Data synchronization (validation) between two clients

I have a webshop built on ASP.NET Boilerplate (Angular frontend and MSSQL database).
The webshop contains items and I want to keep an inventory of these items.
Every time an order is created the inventory is updated. So basically I have a database with Webshops, Items and Orders.
I have repositories and managers for these objects.
All works fine, but the issue occurs when two clients at the same time load the webshop.
Client1 opens webpage:
Webshop1
Item1: "10 items available"
Item2: "8 items available"
Client2 opens webpage at the same time:
Webshop1
Item1: "10 items available"
Item2: "8 items available"
The first one that buys all the available items, should be able to create an order and the second one should get an error.
When an order is created, the backend checks if there are enough items available.
But when the webshop is loaded BEFORE the order of the first client is created, the second client does not know the updated inventory and will be able to create the order as well.
Meaning 20 items of Item1 can be sold!
How do I "sync" the data between the two sessions in the backend? It seems somehow the data is cached in the backend when loading the webshop.
CreateOrder function
public async Task<CreateOrderResponseDto> Create(CreateOrderDto input, long? userId)
{
input.OrderItems.ForEach(async o =>
{
if (!(await _salesItemManager.ReserveStock(o.SalesItemId, o.Quantity)).IsSuccess)
{
throw CodeException.ToAbpValidationException("OrderItem", "OrderItemCreate");
}
});
var salesPage = await _salesPageManager.Get(input.SalesPageId, false);
if (salesPage.GetState() != StatePage.Published)
{
throw CodeException.ToAbpValidationException("Order", "PageNotAvailable");
}
if (salesPage.CommentsRequired.HasValue && salesPage.CommentsRequired.Value)
{
if (string.IsNullOrWhiteSpace(input.Description))
{
throw CodeException.ToAbpValidationException("Order", "CommentsRequired");
}
}
var order = new Order
{
Address = input.Address,
City = input.City,
LastName = input.LastName,
Name = input.Name,
PostalCode = input.PostalCode,
Email = input.Email,
PhoneNumber = input.PhoneNumber,
Description = input.Description,
SalesPage = salesPage
};
try
{
order.Price = await _salesItemManager.GetPriceByOrders(input.OrderItems);
order = await _orderRepository.InsertAsync(order);
input.OrderItems.ForEach(async o =>
{
var orderItem = new OrderItem();
orderItem.SalesItemId = o.SalesItemId;
orderItem.OrderId = order.Id;
orderItem.Quantity = o.Quantity;
await _orderItemRepository.InsertAsync(orderItem);
});
if (input.SelectedSalesPageOptionId.HasValue)
{
order.SalesOption = await _salesPageManager.GetOption(input.SelectedSalesPageOptionId.Value);
}
}
catch (Exception e)
{
throw CodeException.ToAbpValidationException("OrderItem", "OrderItemCreate");
}
if (userId.HasValue && salesPage.User.Id == userId.Value)
{
var payment = await _paymentManager.CreateManualPayment(order, input.IsPaid);
order.Payment = payment;
return new CreateOrderResponseDto() { IsSuccess = true, PaymentUrl = string.Empty, OrderId = order.Id.ToString() };
}
else
{
var payment = await _paymentManager.CreatePayment(order);
order.Payment = payment;
return new CreateOrderResponseDto() { IsSuccess = true, PaymentUrl = payment.PaymentUrl, OrderId = order.Id.ToString() };
}
}
ReserveStock function
public async Task<GeneralDto> ReserveStock(Guid itemId, int quantity)
{
var salesItem = await _salesItemRepository.GetAsync(itemId);
if (salesItem == null || salesItem.Stock == null || salesItem.ReservedStock == null)
return new GeneralDto() { IsSuccess = false };
if (salesItem.Stock < quantity)
{
return new GeneralDto() { IsSuccess = false };
}
salesItem.Stock -= quantity;
salesItem.ReservedStock += quantity;
try
{
await _salesItemRepository.UpdateAsync(salesItem);
}
catch (Exception e)
{
throw CodeException.ToAbpValidationException("SalesItem", "SalesItemUpdate");
}
return new GeneralDto() { IsSuccess = true };
}

The problem is not that the data is cached.
The problem is that your ReserveStock checks are async tasks that are not awaited by the caller:
input.OrderItems.ForEach(async o =>
{
if (!(await _salesItemManager.ReserveStock(o.SalesItemId, o.Quantity)).IsSuccess)
{
throw CodeException.ToAbpValidationException("OrderItem", "OrderItemCreate");
}
});
Assign your async ReserveStock checks to an array of tasks that is awaited by the caller:
var reserveStockChecks = input.OrderItems.Select(async o =>
{
if (!(await _salesItemManager.ReserveStock(o.SalesItemId, o.Quantity)).IsSuccess)
{
throw CodeException.ToAbpValidationException("OrderItem", "OrderItemCreate");
}
}).ToArray();
await Task.WhenAll(reserveStockChecks);

Bug in order program in which payment can be bypassed

This project makes the customer first create an order and them has to pay for said order via Braintree, However the issue that I am getting is that a customer can create an order and them close the application. This will cause the order to still exist however the customer did not have to pay for their order. If any one knows of a work around for this their help would be thanked. (The orders and payments work. Its just this bug that I'm worried about)
Orders Controller
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> FirstClassCreate(FormCollection values)
{
var order = new Order();
TryUpdateModel(order);
var customer = db.Users.FirstOrDefault(x => x.Email == User.Identity.Name);
var cart = ShoppingCart.GetCart(this.HttpContext);
try
{
Sets the order attributes
order.DeliveryDate = DateTime.Now.AddDays(1);
order.DeliveryMethod = "First Class";
order.FirstName = customer.FirstName;
order.LastName = customer.LastName;
order.PostalCode = customer.PostalCode;
order.State = customer.State;
order.City = customer.City;
order.Email = customer.Email;
order.Country = customer.Country;
order.Phone = customer.PhoneNumber;
order.Address = customer.Address;
order.Username = customer.Email;
order.OrderDate = DateTime.Now;
var currentUserId = User.Identity.GetUserId();
order.Total = cart.GetFirstClass();
if (order.SaveInfo && !order.Username.Equals("guest#guest.com"))
{
var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
var store = new UserStore<ApplicationUser>(new ApplicationDbContext());
var ctx = store.Context;
var currentUser = manager.FindById(User.Identity.GetUserId());
//Save this back
//http://stackoverflow.com/questions/20444022/updating-user-data-asp-net-identity
//var result = await UserManager.UpdateAsync(currentUser);
await ctx.SaveChangesAsync();
await storeDB.SaveChangesAsync();
}
Saves the order to the database
//Save Order
storeDB.Orders.Add(order);
await storeDB.SaveChangesAsync();
//Process the order
cart = ShoppingCart.GetCart(this.HttpContext);
order.Total = cart.GetFirstClass();
order = cart.CreateOrder(order);
return RedirectToAction("FirstClass", "Checkouts");
}
catch
{
//Invalid - redisplay with errors
return View(order);
}
}
Checkouts controller
public ActionResult CreateFirstClass(FormCollection collection)
{
var gateway = config.GetGateway();
Decimal amount;
//Need to get the amount
try
{
amount = Convert.ToDecimal(Request["amount"]);
}
catch (FormatException e)
{
TempData["Flash"] = "Error: 81503: Amount is an invalid format.";
return RedirectToAction("New");
}
string nonceFromTheClient = collection["payment_method_nonce"];
var cart = ShoppingCart.GetCart(this.HttpContext);
//if (id == null)
//{
// return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
//}
//order = Orders.FindAsync(id);
Gets the necessary payment methods
var request = new TransactionRequest
{
Amount = cart.GetFirstClass(),
PaymentMethodNonce = nonceFromTheClient,
Options = new TransactionOptionsRequest
{
SubmitForSettlement = true
}
};
cart.EmptyCart();
Result<Transaction> result = gateway.Transaction.Sale(request);
if (result.IsSuccess())
{
Transaction transaction = result.Target;
return RedirectToAction("Show", new { id = transaction.Id });
}
else if (result.Transaction != null)
{
return RedirectToAction("Show", new { id = result.Transaction.Id });
}
else
{
string errorMessages = "";
foreach (ValidationError error in result.Errors.DeepAll())
{
errorMessages += "Error: " + (int)error.Code + " - " + error.Message + "\n";
}
TempData["Flash"] = errorMessages;
return RedirectToAction("New");
}
}
#

MembershipUser not getting updated result from database

I'm building a simple application where a user can edit their profile including adding/deleting a brand image. This seems to be working fine and is updating the database no problem, however when refreshing the page and retrieving the user details via Membership.GetUser() the result includes the old results and not those from the updated database.
Here is my MembershipUser GetUser override:
public override MembershipUser GetUser(string query, bool userIsOnline)
{
if (string.IsNullOrEmpty(query))
return null;
var db = (AccountUser)null;
// ...get data from db
if (query.Contains("#")){
db = _repository.GetByQuery(x => x.Email == query).FirstOrDefault();
}
else
{
string firstName = query;
string lastName = null;
if (query.Contains(" "))
{
string[] names = query.Split(null);
firstName = names[0];
lastName = names[1];
}
// ...get data from db
db = _repository.GetByQuery(x => x.FirstName == firstName && x.LastName == lastName).FirstOrDefault();
}
if (db == null)
return null;
ToMembershipUser user = new ToMembershipUser(
"AccountUserMembershipProvider",
db.FirstName + " " + db.LastName,
db.ID,
db.Email,
"",
"",
true,
false,
TimeStamp.ConvertToDateTime(db.CreatedAt),
DateTime.MinValue,
DateTime.MinValue,
DateTime.MinValue,
DateTime.MinValue);
// Fill additional properties
user.ID = db.ID;
user.Email = db.Email;
user.FirstName = db.FirstName;
user.LastName = db.LastName;
user.Password = db.Password;
user.MediaID = db.MediaID;
user.Media = db.Media;
user.Identity = db.Identity;
user.CreatedAt = db.CreatedAt;
user.UpdatedAt = db.UpdatedAt;
return user;
}
Note I am using a custom MembershipProvider and MembershipUser. Here is where I am calling that method:
public ActionResult Edit()
{
ToMembershipUser toUser = Membership.GetUser(User.Identity.Name, true) as ToMembershipUser;
Now when I do a separate query just under this line of code straight to the database, not invoking MembershipUser, I get the updated result which in turn updates the MembershipUser result?!
It seems it may be caching the results? Anyway around this? I hope this is clear enough. Thanks
Edit:
It appears that when I set a breakpoint just after :
// ...get data from db
db = _repository.GetByQuery(x => x.FirstName == firstName && x.LastName == lastName).FirstOrDefault();
'db' retrieves the outdated results though surely this is talking to the database? If need be I'll update with my repository pattern

I managed to find a workaround though I'm not happy with this solution, so if anyone can improve upon this please post.
I decided to manually update the MembershipUser instance manually each time I update the image. My controller now looks like this:
private static ToMembershipUser MembershipUser { get; set; }
// GET: Dashboard/AccountUsers/Edit
public ActionResult Edit()
{
if(MembershipUser == null)
MembershipUser = Membership.GetUser(User.Identity.Name, true) as ToMembershipUser;
}
[HttpPost]
[ValidateJsonAntiForgeryToken]
public JsonResult UploadMedia(IEnumerable<HttpPostedFileBase> files, int id)
{
var images = new MediaController().Upload(files);
if (images == null)
{
Response.StatusCode = (int)HttpStatusCode.BadRequest;
return Json("File failed to upload.");
}
AccountUser accountUser = db.AccountUsers.Find(id);
db.Entry(accountUser).State = EntityState.Modified;
accountUser.UpdatedAt = TimeStamp.Now();
accountUser.MediaID = images[0];
db.SaveChanges();
MembershipUser.Media = accountUser.Media;
MembershipUser.MediaID = accountUser.MediaID;
return Json(new { result = images[0] });
}
[HttpPost]
[ValidateJsonAntiForgeryToken]
public JsonResult DeleteMedia(int id)
{
bool delete = new MediaController().Delete(id, 1);
if (!delete)
{
Response.StatusCode = (int)HttpStatusCode.BadRequest;
return Json("Error. Could not delete file.");
}
MembershipUser.Media = null;
MembershipUser.MediaID = null;
return Json("Success");
}

Saving changes to user account result in DbUpdateConcurrencyException

I have a form where the user can edit their user account information and then save the new changes.
The problem I'm getting happens when I save the modified changes to the database.
On the line context.SaveChanges(), I get a DbUpdateConcurrencyException exception thrown. It says, "Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries."
I have no idea why.
Here's what I have done:
public ActionResult EditUserAccount()
{
UserAccountViewModel editUserAccountViewModel = new UserAccountViewModel();
editUserAccountViewModel.UserName = UserSession.GetValue(StateNameEnum.UserName, StateNameEnum.UserName.ToString()) as string;
int UserId = WebSecurity.GetUserId(editUserAccountViewModel.UserName);
var userInfo = context.db_user.First(x => x.UserId == UserId);
editUserAccountViewModel.Title = userInfo.Title;
editUserAccountViewModel.FirstName = userInfo.FirstName;
editUserAccountViewModel.LastName = userInfo.LastName;
editUserAccountViewModel.PhoneNumber = userInfo.PhoneNumber;
editUserAccountViewModel.AltPhoneNumber = userInfo.AltPhoneNumber;
editUserAccountViewModel.EmailAddress = userInfo.EmailAddress;
editUserAccountViewModel.UserAccountState = UserAccountViewModel.AccountState.EDIT;
return (PartialView("~/Views/Account/UserAccount.cshtml", editUserAccountViewModel));
}
[HttpPost]
public ActionResult EditUserAccount_Save(UserAccountViewModel editUserAccountViewModel)
{
try
{
if (ModelState.IsValid)
{
editUserAccountViewModel.UserName = UserSession.GetValue(StateNameEnum.UserName, StateNameEnum.UserName.ToString()) as string;
db_user user = new db_user();
user.Title = editUserAccountViewModel.Title;
user.FirstName = editUserAccountViewModel.FirstName;
user.LastName = editUserAccountViewModel.LastName;
user.PhoneNumber = editUserAccountViewModel.PhoneNumber;
user.AltPhoneNumber = editUserAccountViewModel.AltPhoneNumber;
user.EmailAddress = editUserAccountViewModel.EmailAddress;
user.LanguageId = context.languages.Where(t => t.Code == editUserAccountViewModel.Language).Select(t => t.Id).SingleOrDefault();
user.CreatedDate = DateTime.Now;
user.UserId = WebSecurity.GetUserId(editUserAccountViewModel.UserName);
context.Entry(user).State = EntityState.Modified;
context.SaveChanges();
JsonResult res = Json(new { Success = true, data = "", Message = "" });
return res;
}
else
{
JsonResult res2 = Json(new { Success = false, data = "", Message = "" });
return res2;
}
}
return null;
}

You are not creating an instance of context within the controller action, which would imply that it is at the class level. That means that context is shared with every other web request processed by that controller. This part of the error message Entities may have been modified or deleted since entities were loaded seems to confirm that hypothesis.
Instead, create an instance of context in your controller action.
Since you are editing an existing user in this action, you will first need to load the existing user into the context from the database, rather than instantiating a new one as you are now.
I strongly suspect that this change will resolve your issue.
UPDATE
Here's a code example. I don't know what your context class is called, so you might have to change that part. I assume that the user must already exist when this controller is called (based on the name of the method). I removed the try because you are not catching anything. If there is something useful you can do when an exception is thrown, go ahead and put that back in.
[HttpPost]
public ActionResult EditUserAccount_Save(UserAccountViewModel editUserAccountViewModel)
{
if (ModelState.IsValid)
{
using (MyContext context = new MyContext())
{
int userId = WebSecurity.GetUserId(editUserAccountViewModel.UserName);
db_user user = context.DbUsers.Where(u => u.Id == userId).Single();
editUserAccountViewModel.UserName = UserSession.GetValue(StateNameEnum.UserName, StateNameEnum.UserName.ToString()) as string;
user.Title = editUserAccountViewModel.Title;
user.FirstName = editUserAccountViewModel.FirstName;
user.LastName = editUserAccountViewModel.LastName;
user.PhoneNumber = editUserAccountViewModel.PhoneNumber;
user.AltPhoneNumber = editUserAccountViewModel.AltPhoneNumber;
user.EmailAddress = editUserAccountViewModel.EmailAddress;
user.LanguageId = context.languages.Where(t => t.Code == editUserAccountViewModel.Language).Select(t => t.Id).SingleOrDefault();
user.CreatedDate = DateTime.Now;
context.SaveChanges();
JsonResult res = Json(new { Success = true, data = "", Message = "" });
return res;
}
}
else
{
JsonResult res2 = Json(new { Success = false, data = "", Message = "" });
return res2;
}
}