Marauroa Database Structure: Difference between revisions

{{Navigation for Marauroa Top}}

The following diagram shows the all tables used by Marauroa. Games are, however, free to add their own tables if the need arises (JMapacman and Marboard don't need additional tables but Stendhal makes heavy use of [[Stendhal Database Structure|this possibility]].

== Other stuff ==

{{Move everything below these lines into the [[Database Access]] article}}

=== JDBC Database HOWTO===

{{TODO|Update to reflect DAOs}}

{{TODO|Add H2}}

JDBC technology is an API that lets you access virtually any tabular data source from the Java programming language. It provides cross-DBMS connectivity to a wide range of relational databases. Unfortunatally it does not hide vendor specific stuff. Marauroa and Stendhal currently only work with MySQL because of that. Adding support for other database software would be very easy as the database specific code is concentrated in the classes JDBCDatabase (Marauroa) and StendhalPlayerDatabase (Stendhal). We have no need for that, so it was not done, yet. We will, however, accept patches for multi database system support, so if you need it, go ahead.

You need to download MySQL Connector/J in order to get it to run: http://www.mysql.com/downloads/api-jdbc-stable.html

To configure Marauroa to work with a JDBC source, run the appropriate GenerateINI program. For Stendhal this is games.stendhal.server.core.engine.GenerateINI.

Before using the application with the database, you need to create the database itself. So, with MySQL just run MySQL and enter:

<pre>

create database stendhal;

grant all on stendhal.* to stendhal_user@localhost identified by 'stendhal_passwd';

</pre>

The rest of code is handled by the server itself, and it will create the tables if they don't exist.

=== Storing objects in the database ===

Objects are stored in the database to save their state. This is an expensive operation, so it is only done every 10 minutes or on special events (like logout).

This decision is made in RPManager. It calculates how often an object has to be stored.

Marauroa knows two types of objects which can be stored to the database: players and zones. Both objects can contain other objects: Players have items in their bags, zones can contain objects that are flagged as storable.