sort sql by date from 2 different tables

Hi

i have 2 tables.
1 table is a my MAIN MESSAGE POST
the other table is the COMMENTS posted to messages.

my recordset pulls the main message, and then pulls the JOINED comments matching that
what i need to do is the get date field from both tables and have the data sorted by the most recent date.

everything i have tried i either get things sorted by the most recent message where messages with comments do not get identified as newly updated - they are just sorted by the date of the original message.

OR I get the most recent comment posting date, where the new messages posted with no comments go to the end.

What i need is to get the records sorted so that they sort by the most recent.
Recent meaning most recent message posted, or recent comment.

heres the code i have currently for this recordset.
any help would be much appreciated.


<%
Dim rsMainPage
Dim rsMainPage_cmd
Dim rsMainPage_numRows

Set rsMainPage_cmd = Server.CreateObject ("ADODB.Command")
rsMainPage_cmd.ActiveConnection = MM_connBoard_STRING
rsMainPage_cmd.CommandText = "SELECT blg_topic_top.id_top, blg_topic_top.title_top, blg_article_art.id_art, blg_article_art.title_art, blg_article_art.description_art, blg_article_art.date_art , blg_article_art.visible_art, count(blg_comment_com.id_com) AS count_id_com_1, max(blg_comment_com.date_com), blg_article_art.text_art FROM ((blg_topic_top LEFT JOIN blg_article_art ON blg_article_art.idtop_art=blg_topic_top.id_top) LEFT JOIN blg_comment_com ON blg_comment_com.idart_com=blg_article_art.id_art) WHERE blg_article_art.visible_art=1 GROUP BY blg_topic_top.id_top, blg_topic_top.title_top, blg_article_art.id_art, blg_article_art.title_art, blg_article_art.description_art, blg_article_art.date_art, blg_article_art.visible_art, blg_article_art.text_art ORDER BY max(blg_comment_com.date_com) DESC"
rsMainPage_cmd.Prepared = true

Set rsMainPage = rsMainPage_cmd.Execute
rsMainPage_numRows = 0
%>


THANKS
sam

This is a complex scenario to deal with directly in the sql. It might be possible but I'm not sure how you would structure it.

I think it might be best to have a third table to help you organize all of the messages. When a message or comment is inserted you would insert a new record into this table to record the time, the message id and comment id. In the end this would give you a table that has all of the posts organized by the order they were added. Populating this table with the existing records would put you in about the same scenario you are in now though.

This is not an easy problem to solve. The alternative would be to use some php code to hold the data from both tables then sort the data and use that as your order of the records.