Can I have a table with two foreign keys?

Question

I am creating a social media site. Users can create a category (1 user to many categories) and each category has many entries. I want to allow users to post on events (1 event can have many posts).

In other words the event owns the post but I want to be able to identify the user who created that post.

Does this mean that I should create 1 event to many posts as well as 1 user to many posts? Does this create normalization problems. What's the best way around this?

Answer 1

I dont see any relation between category and events
In that case add a categoryID as FK in Events

• Users table

  1. userID Primary key

• Categories table

  1. categoryID Primary key
  2. userID Foreign Key (users)

• Events

  1. eventID Primary key

• Posts

  1. postID Primary key
  2. eventID Foreign Key (events)
  3. userID Foreign Key (users)