Object relational mapping

This document gives you an high-level insight into the ORM powering the backend.

Players and Characters

At the heart of the ORM lays a Game object. It is used to differentiante between multiple game instances as well as being the "glue" inbetween the other objects. Every Game can have multiple Player objects (representing actual humans playing the game) while a Player can only be part of one Game. It is thereby a One-To-Many (n:1) relation. We did not take action to prevent humans from having multiple Player instances. Each Player has a Character (i.e. Pilot), while each Character posseses arbitrary amount of bonus and penalty. Its there by logical to have small, fixed set of Character-classes and form a Many-To-One (don't be confused! One-To-Many and MTO are the same thing, just from diffrent viewpoints) relationship to the Player, so that every Player has exactly one Character but every Character may have multiple Player. Since there can only be one and exactly one "Pilot"-Class in the game, the CharacterType attribute is set to be unique. In conjunction with the CharacterType-Enum, this achives the desired behavior.

Player and Character in the ORM

The Clock

Each Game needs a Clock which defines how fast-pacted the game is. Since one Clock will always belong to only one Game, a One-To-One relation is appropriate. The thought to "re-use" Clocks by making them One-To-Many is not correct. When one Clock is used by multiple Games, they would all run at the same speed (desired behavior), how ever, stopping/pausing one Game would then also stop all other Games. Which is not okay. One could argument to move the Clock into the Game-Object all together, how ever, this "feels" odd to the end user, when creating a new Game. This could be hidden by a nice UI but would need extra work. Using a OTO relation show the logical connection while maintaining a "pretty feeling" distance. But thats an argue about taste.

The clock in the ORM

Parameter

The Parameter are one the most essential parts of the app. Their value is the reason for certain action by the user and they can also be the reason for a Game-Over. By the nature of these Parameter, they all work the same and are only having a diffrent name. This is why the Enum ParameterType is used. Each Parameter belongs to one Game, thereby forming a Many-To-One relationship. It is possible to instanciate the same ParameterType multiple times. It has to be, to allow multiple Games simultaneously.

Parameter in the ORM