Question

I am using Ruby on Rails, but I think this question could be applied to any database design. I am trying to develop my own permissions system.

Is it poor design to have an array of what a user can edit? i.e. a User has a column of can_edit with a value of [Articles, Events, Costs] or a User can_view with a value of [All].

And then I can just run a check on what is being edited. Or is this poor design?

Answer 1

In general, your database design ought to be properly normalized. That would mean that you shouldn’t store multiple values in a single row. You’ll likely be much better served by a design that has three tables

• Permission has columns permission_id and permission_type and lists the valid permissions
• User has a user_id column and lists the value users
• User_Permission is a mapping table between the two. It has columns permission_id and user_id both of which are defined as foreign keys to the Permission and User tables respectively