Question

In my rails app I have a model Events. It has several columns which were created through following this guide https://devcenter.heroku.com/articles/export-from-heroku-postgres and then performing rake db:schema:dump.

Now I want to add some new columns to the Event model. I tried editing schema.rb and restarting the app but that didn’t seem to work. Anyone know the proper way to proceed?

—-Edit——-

Specifically I added this line to the Event model in schema.rb.

t.datetime "date_time"

When I click the link to add a event in the rails app I receive this error:

undefined method `date_time' for #<Event:0x007fdb59a87118>

Answer 1

The schema.rb file is a representation of the current state of the database schema, it is written by the database migration process, not read.

If you want to add a new column, create a migration:

$ rails generate migration AddNewEventStuff
$ vim db/migrate/add_new_event_stuff*.rb

Then add your columns:

class AddNewEventStuff < ActiveRecord::Migration
  def change
    add_column ...
  end
end

Everything except the add_column should be there already. Once you have your migration, do a rake db:migrate and you’re done. Now you should see some changes in your schema.rb.

See the Ruby on Rails Migration Guide for further details and different ways to build your migrations.