为什么date range return空查询？

Question

我尝试为我的渲染创建一个范围，但当我使用 now() 或 date.today() 按日期过滤剧集时，我只有空查询。

models.py:

class Episode(models.Model):
   date = models.DateTimeField(null=True, default=now)

我为进程导入好的库:

from django.utils.timezone import now, timedelta

我认为这是个好方法:

page = 0
n = now()
Episode.objects.filter(date__range=[n-timedelta(days=(5*page)), n-timedelta(days=(5*(page+1)))])
<QuerySet []>

但是没用... 有关信息：数据库中有剧集和输入的值 datetime.datetime :

for e in Episode.objects.filter():
   print(e.date)

2017-02-22 19:12:31.351811+00:00
2017-02-22 19:12:31.418354+00:00
2017-02-22 19:12:31.468889+00:00
2017-02-22 19:12:31.524925+00:00
2017-02-22 19:12:31.599978+00:00
2017-02-22 19:12:31.680029+00:00
2017-02-22 19:12:31.744071+00:00
2017-02-22 19:12:31.803611+00:00
2017-02-22 19:12:31.872156+00:00
2017-02-22 22:24:56.733546+00:00
2017-02-23 19:16:00.600644+00:00

当我在范围内使用字符串直接时，它起作用了...

Episode.objects.filter(date__range=['2017-02-22 19:12:31.351811+00:00','2017-02-22 19:12:31.744071+00:00'])
<QuerySet [<Episode: Episode object>, <Episode: Episode object>, <Episode: Episode object>, <Episode: Episode object>, <Episode: Episode object>, <Episode: Episode object>, <Episode: Episode object>]>

我之前也尝试初始化变量...

n = now()
page = 0
startDate = n-timedelta(days=5*page)
endDate = n-timedelta(days=5*(page+1))
Episode.objects.filter(date__range=[startDate, endDate])
<QuerySet []>

您知道为什么我可以使用 now 或 datetime 进行过滤并且它可以使用字符串吗？

编辑：查询

print(Episode.objects.filter(date__range=[startDate, endDate]).query)
SELECT "table_episode"."id", "table_episode"."card_id", "table_episode"."date", "table_episode"."number", "table_episode"."title", "table_episode"."type_episode", "table_episode"."tag", "table_episode"."url_access" FROM "table_episode" WHERE "table_episode"."date" BETWEEN 2017-02-23 22:46:06.391779 AND 2017-02-18 22:46:06.391779
<QuerySet []>

Answer 1

如果您的页面 = 0

startDate = n  (as page = 0)
endDate = n - 5 days

这转化为在现在开始日期和结束日期之间搜索的查询，在获得 0 个结果之前 5 天

range documentation

Answer 2

感谢@alfredo138923 的帮助。

我 post 为任何一天需要它的人提供解释的解决方案。

page = 0
n = now()
startDate = n-timedelta(days=5*page)     #more recently date
endDate = n-timedelta(days=5*(page+1))   #more older date
Episode.objects.filter(date__range=[endDate, startDate])   #range of 5 days

事实上，当您需要过滤日期时，您会使用 __range，但最近的日期需要排在第二位，旧的日期排在第一位。

page = 0
n = now()
Episode.objects.filter(date__range=[n-timedelta(days=(5*(page+1))), n-timedelta(days=(5*page))])

相同的代码，但合二为一 line/query。

未阅读评论的引用：

__range is calling sql BETWEEN function for which first argument is greater or equal and second one is less or equal. – @iklinac

为什么date range return空查询？

Why date range return empty query?

django

model

python-3.6