Habari\Post::get_revision_data PHP Method

    public function get_revision_data($date)
    {
        $sql = <<<GET_REVISION_DATA
SELECT
id, post_id, change_field, old_value, user_id, min(change_date) as change_date
FROM {revisions}
WHERE
post_id = :post_id
AND change_date > :rev_date
GROUP BY change_field
ORDER BY change_date;
GET_REVISION_DATA;
        return DB::get_results($sql, array('post_id' => $this->id, 'rev_date' => DateTime::create($date)->sql));
    }