我在 model 使用include Mongoid::Timestamps::Created在数据库插入时间，怎么根据日期来作为查询条件，比如我要查询 2 月 24 号的记录，应该怎么办？
http://mongoid.org/en/mongoid/docs/extras.html#timestamps http://mongoid.org/en/mongoid/docs/querying.html 看完这两条你就可以得出结论 where(:created_at.lte => yourdate ) lte == less than or equal gte == greater than or equal lt == less than gt == greater than 如果是等于呢，就直接:created_at => yourdate 所以看文档要一行行看，这是最基本的