obdev/db/migrate/20240117025150_create_join_table_vendor_participant.rb

class CreateJoinTableVendorParticipant < ActiveRecord::Migration[7.1]
  def change
    create_join_table :vendors, :participants do |t|
      # t.index [:vendor_id, :participant_id]
      # t.index [:participant_id, :vendor_id]
    end
  end
end