title: Storing multiple values for a single variable (PDO)
body: <p>I have a MySQL table that stores user emails:</p>
  
  <pre><code>user_id    |    user_phonenumber
  ----------------------------
  id1        |    555-123456789
  </code></pre>
  
  <p>I want to allow the user to store multiple phonenumbers and I don't want to limit the number of numbers a user can be associated with.</p>
  
  <p>What's the best way of structuring my data, and how would a query work in PDO?</p>
  
  <p>For example, should I store them all in the same field with comma separators and then parse the output when the query is returned, or should I use another table and have each row as a separate number with common user_ids? How would a lookup work then (please provide example code if possible)?</p>
  
  <p>Thanks</p>