title: Writing Excel formula to check all rows if they have same IDs but different file names
body: <p>I have a long list of data within an excel sheet, I am going to be changing the file IDs to names instead. The problem is I need to first check whether there are different IDs for the same file name, as this would create a problem. </p>
  
  <p>So for the columns file_id and the column File_name I need help writing a formula that would compare wherther there are two or more IDs for the same file name. </p>
  
  <p>Is this possible?</p>
  
  <p>Thanks</p>
  
  <p><img src="https://i.stack.imgur.com/YtsNO.png" alt="enter image description here"></p>