ruby-on-rails - Rails合并2个查询结果

我想显示最后一个请求>=1.day.ago的第一个用户，然后添加其余用户

  def self.default_scope
    where("last_request >= ?", 1.day.ago) + where("last_request < ? OR last_request is null", 1.day.ago)
  end

此代码引发此错误：

undefined method `merge' for []:Array

我怎么能那样做？
更新
错误栈

NoMethodError - undefined method `merge' for #<Array:0xd16ba90>:
  activerecord (3.2.13) lib/active_record/relation.rb:503:in `with_default_scope'
  activerecord (3.2.13) lib/active_record/relation.rb:167:in `exec_queries'
  activerecord (3.2.13) lib/active_record/relation.rb:160:in `block in to_a'
  activerecord (3.2.13) lib/active_record/explain.rb:34:in `logging_query_plan'
  activerecord (3.2.13) lib/active_record/relation.rb:159:in `to_a'
  will_paginate (3.0.5) lib/will_paginate/active_record.rb:127:in `block in to_a'
  will_paginate (3.0.5) lib/will_paginate/collection.rb:96:in `create'
  will_paginate (3.0.5) lib/will_paginate/active_record.rb:126:in `to_a'

更新2
我正在使用rails_admin，日期时间字段排序不正确
1）按升序排序
2）按降序排列

最佳答案

在您的特定情况下，可以将作用域与

   default_scope where('last_request >= :time OR (last_request < :time OR last_request IS NULL)', time: 1.day.ago).order('last_request DESC')

UPD
这不是activerecord或railsadmin问题，更多信息
ORDER BY ASC with Nulls at the Bottom
Rails: Order with nulls last

关于ruby-on-rails - Rails合并2个查询结果，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/22477934/