Question

我想查找所有记录，比如Posts，今天用Ruby on Rails创建，然后是昨天创建的所有帖子，等等......我该怎么做？

谢谢，

凯文

Answer 1

试试这个：

#Today
Posts.find(:all, conditions: { :created_at => Date.today...Date.today + 1 })
#Yesterday
Posts.find(:all, conditions: { :created_at => Date.today - 1...Date.today })

或者这个（在我看来最好）：

#Today
Posts.find(:all, conditions: ["DATE(created_at) = ?", Date.today] )
#Yesterday
Posts.find(:all, conditions: ["DATE(created_at) = ?", Date.today - 1] )

Answer 2

作为一项规则，我以UTC时区存储服务器上的所有日期，并让UI处理任何时区转换。为了得到你正在正常工作的那种查询，我不得不将传入的日期按到一个首先是UTC特定的时间范围。

require 'date'

class Post < ActiveRecord::Base

  def self.created(a_date)
    return Post.where(created_at: to_timerange(a_date))
  end

  private

  def self.to_timerange(a_date)
    raise ArgumentError, "expected 'a_date' to be a Date" unless a_date.is_a? Date
    dts = Time.new(a_date.year, a_date.month, a_date.day, 0, 0, 0).utc
    dte = dts + (24 * 60 * 60) - 1
    return (dts...dte)
  end

end

然后，您可以拨打

# today
posts = Post.created(Date.today)
# yesterday
posts = Post.created(Date.today - 1)

Answer 3

要使用范围进行查询，我更喜欢以下内容：

yesterday = Date.yesterday
start = yesterday.beginning_of_day
#Fri, 27 Nov 2020 00:00:00 UTC +00:00
end = yesterday.end_of_day
# Fri, 27 Nov 2020 23:59:59 UTC +00:00 - the value here is one second before midnight
# meaning we should use an inclusive range using two dots:
range = start..end

Post.where(created_at: range)

如何使用Ruby on Rails找到今天，昨天等的记录？

3 个答案: