title: Selecting the last 3 characters of a string SQL
body: <p>can someone help me with some SQL I am struggling with. </p>
  
  <p>I need to select the final 3 characters of a field containing a file name (so I can grab the extension of said files).   Ideally, I'd like a count of these values.</p>
  
  <p>Selecting the first 3 characters of a string is simple enough, but I don't know how to select the final 3 - the filenames are all differing lengths. </p>
  
  <p>Thank you. </p>