Hello Im trying to compile this code it works fine with the DataType int Id but I tried to use Guid DataType and I got an error in the operation == part (Cannot be applied to operands of type 'Guid' and 'int') I don't know how to fix it and I don't know why its not working

public async Task<ServiceResponse<GetCharacterDto>> UpdateCharacter(UpdateCharacterDto updatedCharacter)
        {
            ServiceResponse<GetCharacterDto> response = new ServiceResponse<GetCharacterDto>();

         
            try
            {
                var character = await _context.Characters
                    .Include(c => c.User)
                    .FirstOrDefaultAsync(c => c.Id == updatedCharacter.Id);

                if (character.User.Id == GetUserId())
                {
                    character.Name = updatedCharacter.Name;
             
                    character.Intelligence = updatedCharacter.Intelligence;
               

                    await _context.SaveChangesAsync();

                    response.Data = _mapper.Map<GetCharacterDto>(character);
                }
                else
                {
                    response.Success = false;
                }
            }
            catch (Exception ex)
            {
                response.Success = false;
            }

            return response;
        }

          
    }

CodePudding user response：

I used GUID many times and compared with different ways .A Guid is a 128 bit integer which represent as alphnumeric value . They are incompatible for comparison.

For Eample

interger value = 123

Guid Value=01e75c83-c6f5-4192-b57e-7427cec5560d

You can do by these ways

1. By ToString()

If(id.ToString() == guid.ToString() )
{
// logic
}

2. CompareTo :-Recommended approach

if any of property is not guid then convert into guild using `Guid.Parse(value)' then use CompareTo

if(guid.CompareTo(id) == 0)
{
  // logic
}

I dont know this exception due to statement in linq or if (character.User.Id == GetUserId()) statement but you can use these statement both places

Like This

// I am assuming that both are GUID Type
.FirstOrDefaultAsync(c => c.Id.CompareTo(updatedCharacter.Id) ==0);

OR

// I am assuming that both are GUID Type
 if (character.User.Id.CompareTo(GetUserId()) == 0)`

Guid.CompareTo Method