If it's not useful and someone knows a better way, feel free to correct me, it will be for the good of the entire community, I think...
Been looking for one of these for a long time.
1. Make sure you have a working database of your new rev installed on MySQL (preferable a separate PC / laptop)
2. Work all of your new rev files just like being a full new release and you had none before (config, data, new NPC's, etc.)
3. Start login server and game server to make sure it's really working without errors
4. If everything is OK, dump your database to an SQL file
...and now for the "complicated" part...
5. If you had that on a separate PC, copy new rev on your server machine, along with your dumped SQL file
6. Make a separate DB on your server MySQL connection, like l2clean or whatever
7. Make sure you have altered server.properties and login.properties to match your internal / external IP
8. Stop your server (nasty !!!)
9. Go on Navicat to Tools -> Structure Syncronization
10. Left side -> (your connection name) -> (your new rev db)
11. Right side -> (your connection name) -> (your GS db)
12. Press "Compare" button
13. After compare has been done -> press "Run query" button
14. After successful completion go to Tools -> Data Syncronization
15. Left side -> (your connection name) -> (your GS db)
16. Right side -> (your connection name) -> (your new rev db)
17. Go "Advanced" and remove the mark from "Delete records"
Remark: BE SURE YOU REMOVED THAT MARK BEFORE STARTING !!!
18. Press "Preview" button
You will get 6 or 7 errors, tables which you should copy to a temporary DB FROM YOUR NEW REV DB and copy back after completion...
Normally this tables are:
boxaccess
clan_wars
pledge_skill_trees
posts
skill_spellbooks
topic
zone
19. If on "Preview" is everything OK then press "Start" to upgrade
BE SURE YOU HAVE COMPLETED POINT 17 BEFORE !!!
20. Now just dump SQL file of your old DB and copy your new DB instead
21. start your login server
22. start your game server
23. YOU'RE DONE !!!!!
It will take you longer in the first instance, with time will take less and less.
I do not want to be a big mouth but now, after 6 month, it's taking me about 10 minutes top...
-Credits to NoobLady from Romania