小编chr*_*phe的帖子

当我在find_by_sql的查询中使用列别名时,它似乎没有在结果对象中设置,即使我为该属性添加了attr_accessor.

class Country < ActiveRecord::Base

  attr_accessor :average_score

  def self.sorted_by_average_score
    sql = "SELECT country_id, AVG(score) AS average_score, countries.name " +
    "FROM players " +
    "INNER JOIN countries ON players.country_id = countries.id " +
    "GROUP BY country_id "
    Country.find_by_sql(sql)
  end
end

我希望能够做到这一点:

countries = Country.sorted_by_average_score.first.average_score

...但它总是返回nil,即使从查询中确实返回了一个值.

任何人都可以向我解释为什么没有在对象中设置属性？