wow. hmmm..
this is a tough question but there might be a workaround but it definitely will require a lot of work and some fancy tinkering.
I will assume a few things though:
The MAC server is a stand-alone server and is totally dependent on the WinNT for input. No client can directly access it. Secondly, you will need to know how to write dump scripts that dump data into a database or dump data out of a database.
Based on the above, a suggestion could be as follows:
Client access URL on WinNT
Client logs into the site and gets assigned a session ID so the database table
currently will have
NAME SESSION_ID
------- ------------
Jan-Mike 037xd739az-039993a021g
A service (similar to cron jobs in UNIX) executes a mysql dump every 5 minutes or so (if determining who is logged in is critical then you can lessen the time interval) and stores it into a tab delimited file.
Another service (could be written in Perl using Net::FTP or something), FTP's the result into the Mac environment in a specified directory /DesktopFolder/database
You then have another service on the Mac end that reads this data in and updates its own tables.
Obvious problems:
Latency is a big problem.. since there is definitely a time delay.
Another possible solution one that doesn't require all this haggling could be to embed something in your session ID that tells the MAC side that the user is currently logged on and similarly on the WinNT side that the user is logged on. The idea could probably be borrowed from old CGI GET methods with key, value pairs you can have something like:
OS=WINNT&USER=JANMIKE&LOGIN=YES
Before this data is uploaded into the database (assuming it is a valid input string), you can then send this off to the Mac, have MacPerl parse it and have it upload to the database using some Perl DBM module.
Finally you can facilitate the transferring of the files by setting up something like the following:
MySQL (in UNIX at least) install its databases in /usr/local/mysql/data
you can have this in a directory in a Mac mountable partition (using Appleshare or something like KA-Share.. I'm not really sure I know there's Samba for PCs and UNIX). You can then do dumps immediately on this drive and have the MAC see it instantaneously since it claims the shared drive as its own.
Sorry I couldn't be much more of a help. Good luck.
jm