Database Migration

migration

class AlterUsers < ActiveRecord::Migration
  def up
    rename_table("users", "admin_users")
    add_column("admin_users", "username", :string, :limit => 25  )
    change_column("admin_users", "email", :string, :limit => 100 )
    rename_column("admin_users", "password", "hashed_password")
    add_column("admin_users", "salt", :string, :limit => 40 )
    puts "*********ABOUT TO ADD INDEX************"
    add_index("admin_users", "username")
  end

  def down
    remove_index("admin_users", "username")
    remove_column("admin_users", "salt" )
    rename_column("admin_users", "hashed_password", "password")
    change_column("admin_users", "email", :string, :limit => 100 )
    remove_column("admin_users", "username")
    rename_table("admin_users", "users")
  end
end




################## ERROR ##########################

fayimora [simple_cms (master)]$ rake db:migrate VERSION=0
==  AlterUsers: reverting =====================================================
-- remove_index("admin_users", "username")
rake aborted!
An error has occurred, all later migrations canceled:

Index name 'index_admin_users_on_username' on table 'admin_users' does not exist

Tasks: TOP => db:migrate
(See full trace by running task with --trace)
fayimora [simple_cms (master)]$ rake db:migrate VERSION=0
==  AlterUsers: reverting =====================================================
-- remove_index("admin_users", "username")
rake aborted!
An error has occurred, all later migrations canceled:

Index name 'index_admin_users_on_username' on table 'admin_users' does not exist

Tasks: TOP => db:migrate
(See full trace by running task with --trace)