DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded.

Yalçın Mete 80

If you allow, I would like to ask a question.

I want to replace the data I brought with the "public async Task<IActionResult> WriterEditProfile()" method with the "public IActionResult WriterEditProfile(AppUser p)" method.

"DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded." I get an error.

Why does this occur? Is it because one method is "async" and the other method is not "async" that I get this error?

User's image

[HttpGet]
public async Task<IActionResult> WriterEditProfile()
{
    var values = await _userManager.FindByNameAsync(User.Identity.Name);
    return View(values);
}

[HttpPost]
public IActionResult WriterEditProfile(AppUser p)
{
    UserManager userManager = new UserManager(new EfUserRepository());
    userManager.TUpdate(p);
    return RedirectToAction("Index","Dashboard");
}

public class UserManager : IUserService
{
	IUserDal _userDal;
	public void TUpdate(AppUser t)
	{
		_userDal.Update(t);
	}
}

public class EfUserRepository : GenericRepository<AppUser> , IUserDal
{
	
}

 public class GenericRepository<T> : IGenericDal<T> where T : class
 {
	public void Update(T t)
    {
        using var c = new Context();
        c.Update(t);
        c.SaveChanges();
    }
}

Thanks

JasonPan - MSFT 5,891 Microsoft Vendor

Hi @Yalçın Mete,

Try reloading the latest entities before updating, like below.

public void Update(T t)
{
    using var c = new Context();
    var existingEntity = c.Set<T>().Find(t.Id); // reload
    if (existingEntity == null)
    {
        throw new Exception("Entity not found");
    }
    c.Entry(existingEntity).CurrentValues.SetValues(t);
    c.SaveChanges();
}

Best Regards

Jason

Yalçın Mete 80

Hi @JasonPan - MSFT

Can't find "id".

public void Update(T t)
{    using var c = new Context();
    var existingEntity = c.Set<T>().Find(t.Id); // reload
    if (existingEntity == null)
    {
        throw new Exception("Entity not found");
    }
    c.Entry(existingEntity).CurrentValues.SetValues(t);
    c.SaveChanges();
}

User's image

JasonPan - MSFT 5,891 Microsoft Vendor

Hi @Yalçın Mete,

In your scenario, you can constrain through interfaces.

    public interface IEntity
    {
        int Id { get; set; }
    }
    
    public class AppUser : IEntity
    {
        public int Id { get; set; }
        public string? Name { get; set; }
        public string? Email { get; set; }
    }
    
    public class GenericRepository<T> : IGenericDal<T> where T : class, IEntity
    {
        public void Update(T t)
        {
            using var context = new Context();
            var existingEntity = context.Set<T>().Find(t.Id);
            if (existingEntity == null)
            {
                throw new Exception("Entity not found");
            }
            context.Entry(existingEntity).CurrentValues.SetValues(t);
            context.SaveChanges();
        }
    }

Best Regards

Jason

Yalçın Mete 80 Reputation points

2024-07-02T10:57:37.6+00:00
Hi @JasonPan - MSFT
AppUser inherits from the IdentityUser class. I think there is an ID property in IdentityUser (ASP.NET Identity).
With the help of Identity, the ID is automatically created in the table I created in the database.

public class AppUser : IdentityUser<int> { public string NameSurname { get; set; } public string ImageUrl { get; set; } } }

Best Regards
JasonPan - MSFT 5,891 Reputation points Microsoft Vendor

2024-07-03T01:22:09.8566667+00:00

Hi @Yalçın Mete,

Could you create a new repo which can reproduce the issue for me? I need to test in my local, so that I can provide a solution as soon as possible.

Best Regards

Jason

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DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded.

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