Class Diagrams

This week was quite busy. We had to complete our use case diagrams with 3 use cases we hadn’t implemented so far, but which are required until December.

You can find all of our use cases in our documents git here:

One of our new Use Case diagrams

After that, we designed our first database scheme. We wanted to create basic table schemes for relevant data for our use cases. Our first basic database schemes can be found here:

User Entity Relationship Model
Sport Entity Relationship Model

We also created our Software Architecture Document from the .html template, which you can find here:
But for now it is just the template in Markdown because it is the topic of next weeks lecture.

Last but not least we coded our first data object classes for our backend, based on the database scheme. With Spring JPA it’s really easy to work with POJOs (Plain Old Java Objects) and save and access them in a database. You define them as Entities. With the help of repositories you can access their data from the database. Whit that, you don’t have to write a single line of SQL.

After we created the 5 data object classes, it was easy to generate the class diagram from within IntelliJ. You can find the generated class diagram in our git repo here.

Our first UML class diagram for the data object classes

Join the Conversation


  1. Hey Jan,

    your database schemes look very good to me, however if I remember correctly primary keys should be underlined (like UserId).

    Thank you for sharing your progress, its nice to see some class diagrams done well – especially since we can’t really generate them with our architecture approach.

    Best regards,
    Jonas from unitasks (B2)

    1. Hi Jonas,

      thank you for your nice comment and your suggestion for our database scheme.
      We will change that.


  2. Dear Clairvoyance Team,
    it’s nice that you were able to balance such a high workload this week. Your database schema and your uml looks good. But in terms of the database schema you present in your blog, there may be some small improvements. If you want to make it clear that a game requires two teams, you should use Min Max notation. Also, it seems useless that the entity “sports” has no further relationships.

    We are looking forward to you further progress!

    Best regards,
    The hopper team

    1. Hey hopper team,

      thank you for your suggested improvements. We will do further work on our database scheme.

      Best regards,

  3. Hi,
    the database looks very well. It’s a great job, and thank you for your detailed explanation.
    We look forward to your future job.

    Best wishes

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