如何使用纯activerecord (rails)执行此sql

I can't figure out how to manage this purely with active record. I understand it doesn't handle outer joins...

我不知道如何用活动记录来管理这个。我理解它不处理外部连接……

SQL:

SQL:

SELECT * FROM people 
LEFT OUTER JOIN responses 
ON people.id = responses.person_id 
WHERE responses.person_id is NULL;

MODELS:

模型:

Person
id
has_many :responses

Response
id
belongs_to :person

Any suggestions?

有什么建议吗?

1 个解决方案

#1

named_scope :without_responses, :include    => :responses, 
                                :conditions => "responses.id IS NULL"