I think I've played an MMORPG game, called Kings of Caos but am not into them. What programming language are you using? If all you need to do is get data into the database, then you could firstly use MySQL (i know A-Wing has said use Postres but I've never used it), and have a query (a message sent to the database asking for certain rows and columns) for specific data such as usernames, points/credits etc. Then have another one for putting in data, so lets say 'Jim' attacked 'Benny' with 5000 attack points then this data could be automatically put into the database after Benny was attacked. So 5000 could be taken away from his life credits by just having a query seeing how many points he has there then deducting 5000 and altering the current life credits.
You basically have a database with tables in them. If you think of a table as a spreadsheet with rows and columns and the query is selecting the rows and/or columns that you have told the database to search for.
Sorry if I'm talking about a completely different game, but this is sort of what you could do. I'm not an expert but still a learner. Once you get the idea of queries and databases it gets quite easy and from your 'team of codes', they should be able to get into the SQL syntax.
Hope this helps,