BanHammer uses the Bukkit persistance system. This means that you need to configure your bukkit.yml in your server directory with your database settings.

MySQL

This is an example configuration if you wanted to use MySQL. This assumes that it is hosted locally and you want your minecraft database to be minecraft_game. You will need to customise this for your own username and password.

database:
    username: bukkit
    isolation: SERIALIZABLE
    driver: com.mysql.jdbc.Driver
    password: walrus
    url: jdbc:mysql://localhost:3306/minecraft_game

If you get errors when setting this up make sure that you have given your user enough permissions to administrate the database and the database itself does actually exist.

SQlite3

This is the default setting when you setup bukkit for the first time. It creates a sqlite database for each plugin that needs in the plugins data folder. For BanHammer this would be at plugins/BanHammer/BanHammer.db. You can change those folders by changing the settings below.

database:
    username: bukkit
    isolation: SERIALIZABLE
    driver: org.sqlite.JDBC
    password: walrus
    url: jdbc:sqlite:{DIR}{NAME}.db