ruby-on-rails - 我该怎么做呢？ Model.where ("created_at >= #{Time.now - 5.days}")

Question

这一直困扰着我一段时间...

如何字符串插值 datetime在 Rails ActiveRecord 查询中？

# Works, but supeh ugleh:
Model.where("created_at >= ?", Time.now - 5.days)

# How do I do this?
Model.where("created_at >= #{Time.now - 5.days}")
# As is, it produces the following error message:
# ActiveRecord::StatementInvalid: PG::Error: ERROR:  syntax error at or near ...

我关心的原因是代码可读性:

# I like this better:
Model.where("created_at >= #{Time.now - 5.days} OR" + \
            "updated_at >= #{Time.now - 3.days}")

# than this:
Model.where("created_at >= ? OR updated_at >= ?", Time.now - 5.days, Time.now - 3.days)

Answer 1

老问题，但我最喜欢的方法是:

Model.where(created_at: 5.days.ago..Time.current)

更漂亮，更具可读性。

另外， Rails 3.2 introduced一些 Active Support 辅助方法来获取一些常用范围， Time#all_day , Time#all_week , Time#all_quarter和 Time#all_year ，因此您可以例如执行以下操作:

Model.where(created_at: Time.current.all_week)