Rails 3.2 中的活动记录查询问题

Question

我有分类模型，分类有很多帖子。

问题： 有时即使数据库中有记录，也无法在 Web 类别下看到帖子

我通过启用 config.log_level = :debug 调查了生产环境中的操作查询并重新启动了 nginx 乘客服务器。现在我可以看到类别下的记录。我无法再次重现同样的问题，这种情况很少发生。

注：

我没有更改项目中的任何代码。相同的代码表现不同。
Rails 是 3.2.22。 Nginx 乘客(5.1.1)

型号如下

class Category < ActiveRecord::Base
  has_many :postings, conditions: ['paid = ? AND start_date <= ? AND end_date >= ?', true, Date.current, Date.current]
end

class Posting < ActiveRecord::Base
  searchkick

  belongs_to :category

  class << self

    def payed
      where paid: true
    end

    def activated
     where :code => ""
    end

    def starts_on(date)
      where "start_date <= ?", date
    end

    def ends_after(date)
      where "end_date >= ?", date
    end

    def in_location(state,city)
      where(stateid: state.id, cityid: city.id)
    end

    def not_deleted
      where "active != false"
    end
end

帖子管理员

def index
  @category = Category.find(params[:category_id])
  postings = @category.postings.payed.activated.not_deleted.starts_on(Date.current).ends_after(Date.current).order(:created_at)
  @postings = postings.in_location(current_state, current_city).page(params[:page])
end

来自production.log，当访问帖子页面/postings?category_id=25

Category Load (0.2ms) SELECT categories.* FROM categories WHERE categories.id = 25 LIMIT 1

(0.4ms) SELECT COUNT(*) FROM postings WHERE postings.category_id = 25 AND postings.paid = 1 AND postings.code = '' AND postings.stateid = 44 AND postings.cityid = 14823 AND (active != false) AND (paid = 1 AND listing_start_date <= '2017-03-13' AND listing_end_date >= '2017-03-13') AND (listing_start_date <= '2017-03-13') AND (listing_end_date >= '2017-03-13')

CACHE (0. SELECT COUNT(*) FROM postings WHERE postings.category_id = 25 AND postings.paid = 1 AND postings.code = '' AND postings.stateid = 44 AND postings.cityid = 14823 AND (active != false) AND (paid = 1 AND listing_start_date <= '2017-03-13' AND listing_end_date >= '2017-03-13') AND (listing_start_date <= '2017-03-13') AND (listing_end_date >= '2017-03-13')

Posting Load (0.4ms) SELECT postings.* FROM postings WHERE postings.category_id = 25 AND postings.paid = 1 AND postings.code = '' AND postings.stateid = 44 AND postings.cityid = 14823 AND (active != false) AND (paid = 1 AND listing_start_date <= '2017-03-13' AND listing_end_date >= '2017-03-13') AND (listing_start_date <= '2017-03-13') AND (listing_end_date >= '2017-03-13') ORDER BY created_at LIMIT 10 OFFSET 0

以上一组查询没有选取任何记录；在启用调试模式和 restart/touch nginx 服务器后，相同的查询获取了可用记录

是否是活动记录查询/Nginx/缓存问题？

请帮我解决这个问题。

Answer 1

解决了使用 Proc 关联条件如

的问题

has_many :postings, conditions: proc { "payed = 1 AND start_date <= '#{Date.current.to_s(:db)}' AND end_date >= '#{Date.current.to_s(:db)}'"}

如果您已经与 has_many :postings, conditions: ['paid = ? AND start_date <= ? AND end_date >= ?', true, Date.current, Date.current] 等动态条件关联，那么在某些情况下您将获得的结果不是预期的，因为条件将在您开始 Rails 的那一天应用程序和 Date.current 将不再被调用。

感谢何塞 M.Gilgado。参考：http://josemdev.com/articles/dynamic-conditions-associations-rails-3/

Rails 3.2 中的活动记录查询问题

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active-record-query

ruby-on-rails-3.2