Question

您好我在rails中有一个应用程序，我需要从对象中检索创建日期。我知道rails使用时间戳来自动保存这些信息，我看着.json ant它有Created_at信息。问题是如何从对象访问此信息（Created_at）（我的意图是按创建时间排序，并显示此信息）

向任何帮助

Answer 1

您可以通过以下方式访问该媒体资源：

u = User.first   # Let's pretend there's a `User` model within the rails application. Here im getting the first record and storing that user in the variable `u`.

u[:created_at]  # This will give me the value for the `created_at`, for instance: Thu, 18 Oct 2012 14:42:44 UTC +00:00 

or

u.created_at  # will give you the same result

如果您想要sort该字段，您可以（假设有一个User模型）使用sort_by：

User.all.sort_by &:created_at  # This is just a demonstration, you might want to get a sub-set of whatever model you're querying with `where` and some relevant criteria.

或

   User.find(:all, :order => "created_at")  # old and deprecated approach

或

   User.order("created_at DESC") #  more recent approach

如何从rails中的对象获取创建日期？

1 个答案: