Ruby on rails 通过不返回额外属性的sql查找

我正在使用find_by_sql对关系进行左连接计数，如下所示：

scope :popular, lambda{ |since_date = false| 
      query = "select l.*, count(c.id) as popular_count from lists l left join choice_sets c on c.list_id = l.id and c.set_type = 'user'"
      query << "and c.updated_at > " + since_date.strftime("'%Y-%m-%d %H:%M:%S'") if since_date
      query << " group by l.id order by popular_count asc"
      find_by_sql(query)
  }

---

我相信我应该能够访问此属性哈希中的

popular\u count

？我正在使用postgres。

我可以在Rails 3.2（而不是Rails 4）上重现这个问题

我在

app/models/list.rb中有一个名为
popular
的范围和一个名为
pop
的类方法：

class List < ActiveRecord::Base
  scope :popular, lambda{ |since_date = false| 
    query = "select l.*, count(l.id) as popular_count from lists l "
    query << "and l.updated_at > " + since_date.strftime("'%Y-%m-%d %H:%M:%S'") if since_date
    query << " group by l.id order by popular_count asc"
    self.find_by_sql(query)
}

  def self.pop
    since_date = false
    query = "select l.*, count(l.id) as popular_count from lists l "
    query << "and l.updated_at > " + since_date.strftime("'%Y-%m-%d %H:%M:%S'") if since_date
    query << " group by l.id order by popular_count asc"
    find_by_sql(query)
  end

类列表查询您应该能够访问它您是对的。也许ActiveRecord在属性哈希中没有显示为属性。如果您尝试直接调用它，是否会出现错误？是的，我得到一个未定义的错误…可能是因为我试图从范围内调用find_by_sql？可能，但这会很奇怪。也许您需要一个
attr_a主持人：在您的车型上流行的
。
class List < ActiveRecord::Base
  scope :popular, lambda{ |since_date = false| 
    query = "select l.*, count(l.id) as popular_count from lists l "
    query << "and l.updated_at > " + since_date.strftime("'%Y-%m-%d %H:%M:%S'") if since_date
    query << " group by l.id order by popular_count asc"
    self.find_by_sql(query)
}

  def self.pop
    since_date = false
    query = "select l.*, count(l.id) as popular_count from lists l "
    query << "and l.updated_at > " + since_date.strftime("'%Y-%m-%d %H:%M:%S'") if since_date
    query << " group by l.id order by popular_count asc"
    find_by_sql(query)
  end