title: PHP Unique Values from Column in Array
body: <p>I have an array that is generated from a SQL query that I run.  It looks like the following:</p>
  
  <pre><code>$arr[$i]['id'] = $id;
  $arr[$i]['name'] = $name;
  $arr[$i]['email'] = $email;
  </code></pre>
  
  <p>How can I get the unique values from the email column?  I appreciate the help.</p>