Handling Concurrent Updates with Entity Framework Core in C# - StaleDataException Issue
I'm updating my dependencies and I'm working on a project and hit a roadblock. I'm facing a `DbUpdateConcurrencyException` when trying to update an entity that is being modified by multiple requests concurrently in my ASP.NET Core application using Entity Framework Core 6. I have a simple model `Product` with properties `Id`, `Name`, `Price`, and a concurrency token `RowVersion`. Here’s the relevant part of my `Product` class: ```csharp public class Product { public int Id { get; set; } public string Name { get; set; } public decimal Price { get; set; } [Timestamp] public byte[] RowVersion { get; set; } } ``` I am trying to handle the concurrency issue gracefully in my controller. My update method looks like this: ```csharp [HttpPut("{id}")] public async Task<IActionResult> UpdateProduct(int id, Product product) { if (id != product.Id) { return BadRequest(); } _context.Entry(product).State = EntityState.Modified; try { await _context.SaveChangesAsync(); } catch (DbUpdateConcurrencyException) { if (!ProductExists(id)) { return NotFound(); } else { // Here I want to handle the concurrency issue return Conflict(new { message = "The product was updated by another user. Please reload and try again." }); } } return NoContent(); } ``` The problem arises when two clients try to update the same product at almost the same time. One of the requests will succeed, while the other throws a `DbUpdateConcurrencyException`. I want to ensure that when the exception happens, I can provide meaningful feedback to the user and allow them to retrieve the latest state of the entity. I’ve tried a couple of approaches such as fetching the latest data after the exception, but that seems to be leading to additional database calls and potential performance issues. What is the best way to handle this situation? Should I be using optimistic concurrency or is there a better design pattern that could help manage concurrent updates more effectively? This is part of a larger service I'm building. What's the best practice here? The stack includes C# and several other technologies.