Rails 5.1.0 how to upgrade

Question

Rails 5.1.0 introduces the bigint primary keys and foreign keys.

All new tables will have bigint pk and creating a reference migration to an old table will not work since the old pk is a normal int.

Using change_column _, :id,:bigint just errors with a foreign key is pointing towards it, not to mention all the manual labour of finding all the tables and which has which key that needs to be modified.

How do I migrate my production database all my tables to use bigint pk and fk's?

Ofcourse since it's production rails db:drop rails db:setup is not an option.

Answer 1

I facing the same problem. Temporary remove fk's should work. The goal is to change all primary keys from int to bigint.

class ChangeForeignKeysToBigInt < ActiveRecord::Migration[5.1]
  def change

    remove_foreign_key "event_users", "events"

    change_column :event_users, :event_id, :bigint
    change_column :events, :id, :bigint

    add_foreign_key "event_users", "events"

  end
end

you have to do that with all your tables and foreign key columns maybe handle indices the same way, i dont tested that