class CreateChatAccounts < ActiveRecord::Migration[5.2] def change create_table :chat_accounts do |t| t.references :account, foreign_key: { on_delete: :cascade }, null: false t.references :tag, foreign_key: { on_delete: :cascade }, null: false t.index [:account_id, :tag_id], unique: true t.index [:tag_id, :account_id] t.timestamps end end end