Error In Update Record (The instance of entity type 'x' cannot be tracked)

Question

I have this error when update record in RoleRepository.cs.
i use AsNoTracking but show error again

The instance of entity type 'ApplicationRole' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

RoleController.cs

  public async Task<IActionResult> Edit(string id)
        {
            if (id == null)
            {
                return NotFound();
            }
            if (!await _roleService.ExsistIdAsync(id))
            {
                return NotFound();
            }
            return PartialView(await _roleService.GetAsync(id));
        }

public async Task<IActionResult> Edit(RoleViewModel role)
        {                  
                if (await _roleService.ExsistNameAsync(role))
                {
                   //show message duplicate name
                }
                await _roleService.UpdateAsync(role);
                return Json(new { res = true, model = role });

        }

RoleService.cs

public async Task<IdentityResult> UpdateAsync(RoleViewModel role)
    {
        var mapped = ObjectMapper.Mapper.Map<ApplicationRole>(role);
        return await _roleRepository.UpdateAsync(mapped);
    }

RoleRepository.cs

  public async Task<IdentityResult> UpdateAsync(ApplicationRole role)
        {
            return await _roleManager.UpdateAsync(role);
        }
    public async Task<ApplicationRole> GetAsync(string Id)
        {
            return await _db.Roles.Where(x=>x.Id==Id).AsNoTracking().FirstOrDefaultAsync();
        }

what's the problem ?

Answer 1

Encountered this myself today.

Any entities queried using AsNoTracking can not be used somewhere in the Entity tree of any that I do add/update.

i.e. where you are querying for Role AsNoTracking, you can not then update it, or any dependent entity queried with AsNoTracking.

Answer 2

Consider changing your repository class to scoped if it is singleton

https://stackoverflow.com/questions/48202403/instance-of-entity-type-cannot-be-tracked-because-another-instance-with-same-key

Answer 3

Please consider making your repository class scoped if it is a singleton