The second parameter for oci_fetch_array() is hardcoded, when calling this function inside Zend_Db_Statement_Oracle::fetch(). As a result when the fetchMode property of the database adapter is set to any of Zend_Db::FETCH_NUM, Zend_Db::FETCH_ASSOC, Zend_Db::FETCH_BOTH or Zend_Db::FETCH_BOUND the returned row doesn't contain the columns that have null values.

Maybe this can be made configurable (of course Zend_Db_Statement_Oracle class can be extended and the fetch() method overridden, but I think it would much nicer to allow client code to specify additional flags for the second parameter of the oci_fetch_array() function.

The problem code is written below:

switch ($style) {
            case Zend_Db::FETCH_NUM:
                $row = oci_fetch_array($this->_stmt, OCI_NUM | $lob_as_string);
                break;
            case Zend_Db::FETCH_ASSOC:
                $row = oci_fetch_array($this->_stmt, OCI_ASSOC | $lob_as_string);
                break;
            case Zend_Db::FETCH_BOTH:
                $row = oci_fetch_array($this->_stmt, OCI_BOTH | $lob_as_string);
                break;
            case Zend_Db::FETCH_OBJ:
                $row = oci_fetch_object($this->_stmt);
                break;
            case Zend_Db::FETCH_BOUND:
                $row = oci_fetch_array($this->_stmt, OCI_BOTH | $lob_as_string);
                if ($row !== false) {
                    return $this->_fetchBound($row);
                }
                break;
            default:
                /**
                 * @see Zend_Db_Adapter_Oracle_Exception
                 */
                require_once 'Zend/Db/Statement/Oracle/Exception.php';
                throw new Zend_Db_Statement_Oracle_Exception(
                    array(
                        'code'    => 'HYC00',
                        'message' => "Invalid fetch mode '$style' specified"
                    )
                );
                break;
        }