Rails アプリケーションに独自のタグ実装があり、ActsAsTaggableOn gem に置き換えたいと考えていました。移行を生成し、タグを含むすべての移行を削除しましたが、最初にロールバックするのを忘れていたので、db:reset をレーキしました。これで、スキーマはタグとタグ付け可能で問題ないように見えますが、コンソールでタグを試してみると、タグを入力するだけで取得できます
NameError: uninitialized constant Tag
このエラーの原因は、 Railscastで好きだったと思います。
私の schema.rb は次のようになります。
# encoding: UTF-8
# This file is auto-generated from the current state of the database. Instead
# of editing this file, please use the migrations feature of Active Record to
# incrementally modify your database, and then regenerate this schema definition.
#
# Note that this schema.rb definition is the authoritative source for your
# database schema. If you need to create the application database on another
# system, you should be using db:schema:load, not running all the migrations
# from scratch. The latter is a flawed and unsustainable approach (the more migrations
# you'll amass, the slower it'll run and the greater likelihood for issues).
#
# It's strongly recommended to check this file into your version control system.
ActiveRecord::Schema.define(:version => 20121009203921) do
create_table "comments", :force => true do |t|
t.text "content"
t.integer "user_id"
t.integer "message_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "events", :force => true do |t|
t.string "name"
t.datetime "start_at"
t.datetime "end_at"
t.integer "user_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "messages", :force => true do |t|
t.text "content"
t.integer "user_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
create_table "taggings", :force => true do |t|
t.integer "tag_id"
t.integer "taggable_id"
t.string "taggable_type"
t.integer "tagger_id"
t.string "tagger_type"
t.string "context", :limit => 128
t.datetime "created_at"
end
add_index "taggings", ["tag_id"], :name => "index_taggings_on_tag_id"
add_index "taggings", ["taggable_id", "taggable_type", "context"], :name => "index_taggings_on_taggable_id_and_taggable_type_and_context"
create_table "tags", :force => true do |t|
t.string "name"
end
create_table "users", :force => true do |t|
t.string "name"
t.string "email"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
t.string "encrypted_password"
t.string "salt"
t.boolean "admin", :default => false
t.string "phone"
t.string "street"
t.string "zip"
t.string "location"
end
add_index "users", ["email"], :name => "index_users_on_email", :unique => true
end
ご協力いただきありがとうございます！