public function column($field = 'ID')
    {
        $fieldExpression = $this->expressionForField($field);
        $query = $this->getFinalisedQuery(array($field));
        $originalSelect = $query->getSelect();
        $query->setSelect(array());
        $query->selectField($fieldExpression, $field);
        $this->ensureSelectContainsOrderbyColumns($query, $originalSelect);

        return $query->execute()->column($field);
    }