Question

i am currently writing a webapp in rails where users can mark items as favorites and also block them. I came up two ways and wondered which one is more common/better way.

1. Separate join tables

Would it be wise to have 2 tables for this? Like:

users_favorites
  - user_id
  - item_id

users_blocked
  - user_id
  - item_id

2. single table

users_marks (or so)
  - users_id
  - item_id
  - type (["fav", "blk"])

Both ways seem to have advantages. Which one would you use and why?

Answer 1

The second one has at least the advantage (if the primary key is users_id + item_id) to make sure that no user will have an item both as favorited and blocked.

I suppose I would got with that second solution — especially considering the two tables, in the first solution, would have the same structure, which seems strange ; and it also allows you to have all the information in the same place, which might help, in some cases (reporting, for instance ? ).