class CreateLvaSemesterJoinTable < ActiveRecord::Migration def self.up create_table :lvas_semesters, :id=>false do |t| t.integer :lva_id t.integer :semester_id end add_index :lvas_semesters, [:lva_id, :semester_id] add_index :lvas_semesters, :semester_id end def self.down drop_table :lvas_semesters end end