Bizarre PHP error: function not recognizing its own parameter
<p>I have the following function:</p>

<pre><code>  public function updateCustomerInternetBanking($value, $column_to_go_by)
  {
    $sql = "
      UPDATE customer c
        JOIN account_import ai ON c.account_import_id = ai.id
        JOIN generic_import gi ON ai.generic_import_id = gi.id
        JOIN import_bundle ib ON gi.import_bundle_id = ib.id
         SET has_internet_banking = 1
       WHERE c.".$column_to_go_by." = ".$this-&gt;quote($value)."
         AND ib.id = ".$this-&gt;quote($this-&gt;getId())."
    ";

    $conn = Doctrine_Manager::connection();
    $conn-&gt;execute($sql);
  }
</code></pre>

<p>When I try to run it in development, it works fine. When I try to run it in production, I get this:</p>

<pre><code>PHP Notice:  Undefined variable: column_to_go_by in /var/www/mcif/lib/model/doctrine/ImportBundle.class.php on line 655
</code></pre>

<p>How could <code>$column_to_go_by</code> be undefined?!</p>

<p>And just so you know, this code is copied straight from production and I checked that the <code>WHERE</code>... line is line 655.</p>
