title: How to find duplicates in mysql table using PHP?
body: <p>I have a table with customer info. Normally, the PHP checks for duplicates before they new rows are inserted. However, I had to dump a lot of older rows manually and now that they are all in my table, I need to check for duplicates.</p>
  
  <p>Example rows:</p>
  
  <p>id, name, email, phone, fax</p>
  
  <p>I would like to do a mysql query that will show all ID's with matching emails. I can modify the query later for phone, fax, etc.</p>
  
  <p>I have a feeling I will be using <code>DISTINCT</code>, but I am not quite sure how it's done.</p>