2010-12-02 101 views
7

我有这个模式:发布belongs_to类别和类别has_many发布。 邮政和类别与宝石globalize3Rails 3包括翻译globalize3 activerecord

class Post < ActiveRecord::Base 
    belongs_to :category 
    translates :title, :excerpt, :desC# globalize3 
end 

class Category < ActiveRecord::Base 
    has_many :posts 
    translates :name # globalize3 
end 

在我的PostsController全球化我与这行代码的所有帖子:

def index 
    @posts = Post.includes([:translations, {:category => :translations}]) 
end 

的问题是,我有类翻译N + 1查询问题表:

Post Load (0.3ms) SELECT "posts".* FROM "posts" 

Post::Translation Load (0.3ms) SELECT "post_translations".* FROM "post_translations" WHERE ("post_translations".post_id IN (2,3,4)) 

# START n+1 query block 
Category Load (1.9ms) SELECT "categories".* FROM "categories" WHERE ("categories"."id" IN (9,12,11)) 
Category::Translation Load (0.4ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 9) AND ("category_translations"."locale" IN ('it')) 
CACHE (0.0ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 9) AND ("category_translations"."locale" IN ('it')) 
Category::Translation Load (0.2ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 12) AND ("category_translations"."locale" IN ('it')) 
CACHE (0.0ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 12) AND ("category_translations"."locale" IN ('it')) 
Category::Translation Load (0.2ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 11) AND ("category_translations"."locale" IN ('it')) 
CACHE (0.0ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id = 11) AND ("category_translations"."locale" IN ('it')) 
# END n+1 query block 

Category::Translation Load (0.5ms) SELECT "category_translations".* FROM "category_translations" WHERE ("category_translations".category_id IN (9,12,11)) 

我该如何解决这个n + 1查询问题?

回答

11

您应该在模型中启用急切的翻译加载。推荐的方式来做到这一点是:

class Category < ActiveRecord::Base 
    has_many :posts 
    translates :name # globalize3 

    default_scope includes(:translations) 
end 
2

轨道4

class Category < ActiveRecord::Base 
    has_many :posts 
    translates :name 

    default_scope { includes(:translations) } 
end 
:以从米哈尔Szajbe答案,这仍然有轻微的改装工程