QuestsConverter is a plugin which permits transfer of player data between storage implementations. Both to - and from - YAML and MySQL are currently supported.

The only command is /qconvert playerdata [source] [target] with permission qconvert.all
Setup is a two-step process:

1. Install and run a compatible version of Quests, then configure the MySQL settings.
2. Download the QuestsConverter jar and place it in your server's /plugins folder. Restart the server!