Rails: join across two columns - ruby-on-rails

Question

I'm building a dating app, and I'm creating a table (and model) for when users rate each other (like/dislike). I'm supporting multiple genders, so I don't want to simply have columns for "man's ID" and "woman's ID". However, that means I simply have two users IDs, and need to search both for the current user's ID.
I've managed to get the migration to work, but not to get the actual class to work. I can't figure out how to tell Rails to search both columns.
Ratings migration:
class CreateRatings < ActiveRecord::Migration[6.0]
def change
create_table :ratings do |t|
t.references :event, null: false, foreign_key: true
t.references :user1, index: true, null: false, foreign_key: {to_table: :users}
t.references :user2, index: true, null: false, foreign_key: {to_table: :users}
t.timestamps
end
end
end
Ratings model:
class Rating < ApplicationRecord
belongs_to :event
belongs_to :user1, class_name: "User"
belongs_to :user2, class_name: "User"
end
When I try it in irb, I get:
irb(main):003:0> User.first.ratings
User Load (3.0ms) SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1 [["LIMIT", 1]]
Traceback (most recent call last):
ActiveRecord::StatementInvalid (PG::UndefinedColumn: ERROR: column ratings.user_id does not exist)
LINE 1: SELECT "ratings".* FROM "ratings" WHERE "ratings"."user_id" ...
^
HINT: Perhaps you meant to reference the column "ratings.user1_id" or the column "ratings.user2_id".
irb(main):004:0>
Does this just need to be left out of Rails association-land? e.g. Should I instead define a method in the User class to get records matching Ratings.user1=User.id OR Ratings.user2=User.id?
I'm using a Postgres database, if that allows any cool solutions.
Users migration:
class CreateUsers < ActiveRecord::Migration[6.0]
def change
create_table :users do |t|
t.string :name, null: false
t.string :email, null: false
<snip>
t.timestamps
end
add_index :users, :email, unique: true
end
end
Users model
class User < ApplicationRecord
has_many :ratings
end

Answer 1

If you do not specify a foreign key, a default user_id will be looked for, but it does not exist, hence the error message you are getting. So you can do:
class Rating < ApplicationRecord
belongs_to :event
belongs_to :user1, class_name: "User", :foreign_key => 'user1'
belongs_to :user2, class_name: "User", :foreign_key => 'user2'
end
class User < ApplicationRecord
has_many :ratings1, foreign_key: :user1, class_name: 'Rating'
has_many :ratings2, foreign_key: :user2, class_name: 'Rating'
end
Then you can do
user.ratings1.first and user.ratings2.first
To display both, you need a method like:
def all_user_ratings
Rating.where("user1 = ? OR user2 = ?", user.id, user.id)
end