Build your entity-relationship diagram

The first step of any data modeling exercise is to build a diagram to show the entities in your application and how they relate to each other.

In the application, you have the following entities:

• User

• Game

• UserGameMapping

A User entity represents a user in the application. A user can create multiple Game entities, and the creator of a game will determine which map is played and when the game starts. A User can create multiple Game entities, so there is a one-to-many relationship between Users and Games.

Finally, a Game contains multiple Users and a User can play in multiple different Games over time.

Thus, there is a many-to-many relationship between Users and Games. You can represent this relationship with the UserGameMapping entity.

With these entities and relationships in mind, the entity-relationship diagram is shown below.

Next, we will take a look at the access patterns the data model needs to support.