Sorry to say saszuke that the idea of free sharing of information on this board is not universally enjoyed here.
To make +30 ingame, you need to change the reinforce fail rate of your server to reduce it to 0 failures by editing the appropriate .bin files. Then you can simply buy the reinforcement stones and reinforce as high as your server will tolerate.
To do it via SQL you need to modify the right values in the attrs byte array that each item has. You will need to research for yourself how to decode those attribute values. The item must already exist for that. For either of these you need direct access to the server .bin files and database.