I'm trying to figure out how to use Zend_Db_Table_Abstract correctly. I want to return just the name column from my query. Can you please explain what's wrong with the following code?

class Model_DbTable_Foo extends Zend_Db_Table_Abstract
{
  protected $_name = 'foo';

  public function getFooById($id) {
    $select = $this->select(true)->columns('name')->where('id=' . $id);
    $row    = $this->fetchRow($select);
    print_r($row->toArray());
  }
}