为什么迁移不起作用

Question

I have a migration AddAuthenticableToUser. (rake db:migrate:up VERSION=..) works fine, but when I'm trying to rollback a migration (rake db:migrate:down VERSION=..) it doesn't works. Any errors or warnings. Could you help me with this?

def self.up
  change_table :users do |t|
    t.token_authenticatable
  end
  add_index :users, :authentication_token, :unique => true
end

def self.down
  remove_index :users, :authentication_token                                                                                                                      
  remove_column :users, :authentication_token
end                                                                                                                                                                                                                                                                                                                                         

Answer 1

This should be the trick. I think you named your table token_authenticatable and then tried to remove authentication_token.

def self.up
  create_table :reviews do |t|
    t.column :authentication_token
  end
  add_index :users, :authentication_token, :unique => true
end

def self.down
  remove_index :users, :authentication_token                                                                                                                      
  remove_column :users, :authentication_token
end