Require help in setting up schema

Schema & Data
1

Hey DF Community,

I am a newbie and requires help on setting schema for database for my new app. The requirements are mentioned below:

Tables

  1. User Table (Already defined in the system)
  2. Groups Table
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  3. Comments
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Requirements

  1. Users are able to form new groups.
  2. Users who create the group are assigned admin to the group and have ability to add/ remove other users to the group and even delete a group.
  3. Users who are not admin to the group have only the options to join a group by a sending a request and leaving the group.
  4. And off course, no user should be able to hack others’ comments.

Questions

  1. How to create roles allowing a user to become a group administrator?
  2. How to change roles for users who just created a group to be now called a group administrator?

Notes

  1. The schema I have created here is based on my understanding. Please change it if you think it’s needed.
2

You might want to provide more info on what you have tried, and what did or did not work. Generally speaking, “build-my-app-for-me” type of questions won’t garner much attention.