Best way to verify that a timeclock was approved?

Hi!

I'm looking to determine if a timeclock has not been approved yet. I see that there are three fields related to this matter: approved_by, approved_time and approved_notes. When the timeclock has not been approved, approved_by = 0, approved_time = 0 and the approved_notes field is empty. Is it correct to verify if a timeclock has not been approved by checking that the approved_by field is 0? Or is there a more correct way to do this?

Thanks for your help!