干掉活动记录查询答案

【问题标题】：DRYing up Active Record Queries干掉活动记录查询
【发布时间】：2011-03-09 12:57:54
【问题描述】：

我有 2 个相似的查询，我怎样才能把它们弄干？两个查询之间只有 1 个条件不同。

if self.gender_target == "Both"
  return Drop.limit(180).live.where(
  :drops => {:navigation_section_id => 1}  
  ).group(:id).joins(:categories).where(
  :categories => {:id => self.categories}
  ).all
end

if self.gender_target != "Both"
  return Drop.limit(180).live.where(
  :drops => {:navigation_section_id => 1}, 
  :drops => {:gender_target => ["Both", self.gender_target]} #extra condition
  ).group(:id).joins(:categories).where(
  :categories => {:id => self.categories}
  ).all
end

【问题讨论】：

标签： ruby-on-rails-3 activerecord active-relation

【解决方案1】：

@drops = Drop.limit(180).
              live.
              where(:drops => {:navigation_section_id => 1}).
              group(:id).
              joins(:categories).
              where(:categories => {:id => self.categories})

if self.gender_target != "Both"
  @drops = @drops.where(:drops => {:gender_target => ["Both", self.gender_target]})
end

return @drops.all

【讨论】：