これは私の移行ファイルです:
class AddSeoMetaInfoToArticles < ActiveRecord::Migration
def self.up
add_column :articles, :seo_title, :string, { :default => "", :null => false }
add_column :articles, :seo_description, :string, { :default => "", :null => false }
add_column :articles, :seo_keywords, :string, :string, { :default => "", :null => false }
end
def self.down
remove_column :articles, :seo_keywords
remove_column :articles, :seo_description
remove_column :articles, :seo_title
end
end
'rake db:migrate'を実行しようとすると、次のエラーが発生します
$ rake db:migrate
AddSeoMetaInfoToArticles: migrating =======================================
-- add_column(:articles, :seo_title, :string, {:default=>"", :null=>false})
-> 0.0341s
-- add_column(:articles, :seo_description, :string, {:default=>"", :null=>false})
-> 0.0100s
-- add_column(:articles, :seo_keywords, :string, :string, {:default=>"", :null=>false})
rake aborted!
An error has occurred, this and all later migrations canceled:
wrong number of arguments (5 for 4)
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
私はレールに比較的慣れていないので、何が間違っているのかわかりません。これはRails3.0.9であり、違いが生じる場合はPostgresデータベースです。