Rails association with multiple foreign keys

Question

I want to be able to use two columns on one table to define a relationship. So using a task app as an example.

Attempt 1:

class Use         


        

Answer 1

Extending upon @dre-hh's answer above, which I found no longer works as expected in Rails 5. It appears Rails 5 now includes a default where clause to the effect of WHERE tasks.user_id = ?, which fails as there is no user_id column in this scenario.

I've found it is still possible to get it working with a has_many association, you just need to unscope this additional where clause added by Rails.

class User < ApplicationRecord
  has_many :tasks, ->(user) {
    unscope(:where).where(owner: user).or(where(assignee: user)
  }
end