title: Check for Invalid UPC in MySQL
body: <p>I have a mysql table with a colummn of UPC codes.</p>
  
  <p>How would I go about checking for invalid ones?</p>
  
  <p>There is a site here <a href="http://www.ehow.com/how_6810204_verify-upc-number.html" rel="nofollow">http://www.ehow.com/how_6810204_verify-upc-number.html</a> which shows the procedure for verifying a UPC, but how would one translate this into a mysql query or function.</p>