Rails environment migration error

Question

I was doing migrations with development mode , then I couldn't heroku run rake . Then I found that I should run in production mode. And when I tried to do that (btw using c9.io):

Running via Spring preloader in process 8978
== 20160426150318 AddStatusToBPages: migrating ================================
-- add_column(:b_pages, :status, :string)
   -> 0.0012s
-- add_index(:b_pages, :status)
   -> 0.0037s
-- t()
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

undefined local variable or method `t' for #<AddStatusToBPages:0x00000004f31638>/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:664:in `block in method_missing'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `block in say_with_time'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `say_with_time'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in `method_missing'
/home/ubuntu/workspace/db/migrate/20160426150318_add_status_to_b_pages.rb:5:in `change'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:608:in `exec_migration'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:592:in `block (2 levels) in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:591:in `block in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in `with_connection'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:590:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:998:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in `transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:997:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:959:in `block in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `each'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in `up'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `block in load'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
-e:1:in `<main>'
NameError: undefined local variable or method `t' for #<AddStatusToBPages:0x00000004f31638>
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:664:in `block in method_missing'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `block in say_with_time'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `say_with_time'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in `method_missing'
/home/ubuntu/workspace/db/migrate/20160426150318_add_status_to_b_pages.rb:5:in `change'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:608:in `exec_migration'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:592:in `block (2 levels) in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:591:in `block in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in `with_connection'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:590:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:998:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in `transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:997:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:959:in `block in migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `each'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in `up'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `block in load'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
-e:1:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

my status_to_b_pages migration:

     class AddStatusToBPages < ActiveRecord::Migration
  def change
    add_column :b_pages, :status, :string
    add_index :b_pages, :status
    t.string :status
  end
end

Answer 1

It's complaining about the

t.string :status

You don't need that. You would only use the t. format when running a migration that creates a table. Here, the table already exists and the add_column and add_index are all you need.

There is no t variable here, so that's why the migration complains.

Answer 2

Correct should be

class AddStatusToBPages < ActiveRecord::Migration
  def change
    add_column :b_pages, :status, :string
    add_index :b_pages, :status, :string
  end
end