How to write SQL in a migration in Rails

Question

I have the following SQL which I need to do

CREATE TABLE cars_users2 AS SELECT DISTINCT * FROM cars_users;

DROP TABLE cars_users;

ALTER TABLE cars_users2 R         


        

Answer 1

You could try to use the execute method.

Something like this (it's untested, some kind of brainchild)

class UpdateCarUserTable < ActiveRecord::Migration
  def up
    execute "CREATE TABLE cars_users2 AS SELECT DISTINCT * FROM cars_users"
    execute "DROP TABLE cars_users"
    execute "ALTER TABLE cars_users2 RENAME TO cars_users"
  end

As there is no equivalent down method, an ActiveRecord::IrreversibleMigration should be raised when trying to migrate down.