急。。求助HQL问题

[lightcyf]

现在我有两张表：message、reply，映射关系已建好，现在我要实现下面的sql对应的hql应该如何写？

SELECT message.messageID, message.messageTitle, message.messageContent, message.messageDate, isnull(r.count, 0)
FROM Message AS message LEFT OUTER JOIN
(SELECT COUNT(*) AS count, messageID
FROM Reply
GROUP BY messageID) AS r
ON message.messageID = r.messageID