So I started designing the DB using this cool tool. The project has 2 tables, users and categories . The user can create many categories as he wants so the first approach I took was creating a third table, a union table to store user_id and category_id. With this solution the users are able to create x numbers of categories and we can see assign the category to the user. - Source: dev.to / 3 months ago

Once you have generated the SQL code, you can convert it into a relational schema (the graphical table model) using DrawSQL. This tool offers:. - Source: dev.to / 3 months ago

DrawSQL makes it easy for teams to collaborate on creating and maintaining schema diagrams. With a single source of truth, there's no need for manually syncing diagram files between different developers and offline tools anymore. Source: almost 2 years ago

To be honest, since you are just getting started, I think you should reconsider simplifying this app to begin with. Built something easier and get some more experience before jumping in the ocean. Maybe start by focusing only on the parent company and sub-companies. However, I strongly recommend you to try and make a diagram of your database with relations and columns as it can you a lot of time. I personally use... Source: almost 2 years ago

After googling some, I found DrawSQL, which is a start. But I don't like its interface, and the inability to download the schemas in any form (at least not from what I can see). Source: over 2 years ago

Notionway.com and notionthings.com are some to get you started. Source: over 2 years ago