Django,按日期范围中指定的月份和年份筛选

2024-05-18 04:26:56 发布

您现在位置:Python中文网/ 问答频道 /正文

我有下列型号

class Destination_Deal(models.Model):
    name = models.CharField(_("Nombre"),max_length=200)

class Departure_Date(models.Model):
    date_from= models.DateField(_('Desde'))    
    date_to= models.DateField(_('Hasta'))
    destination_deal = models.ForeignKey(Destination_Deal,verbose_name = _("Oferta de Destino"))

这是出发日期表中的实际数据

id  date_from   date_to     destination_deal_id
1   2012-11-01  2013-03-17  1
2   2012-11-01  2012-12-16  2
3   2012-09-16  2012-10-31  3
4   2012-11-01  2012-12-16  3
5   2013-01-04  2013-01-11  4

如果指定的月份和年份介于起始日期和结束日期之间,我想筛选目标交易。

示例1

Month: September (09)
Year: 2012

想要的出发日期结果:
ID 3:这是唯一一个触及09/2012的数据范围

示例2

Month: February (02)
Year: 2013

想要的出发日期结果:
ID 1:02/2012在03/2012之前

所以,日子其实并不重要。如果月份和年份介于日期从和日期到之间,即使是在某一天,也必须进行筛选。

我想我必须用一些类似this的东西,但我不知道怎么做。

提前谢谢! 米格尔

---编辑---
这是对来自Aamir Adnan的答案的测试,但它没有像我预期的那样工作,因为ID 1也必须返回,因为它从2012年11月到2013年3月,所以2013年1月介于两者之间。

Departure_Date.objects.all()
[<Departure_Date: id: 1 - from: 2012-11-01 - to: 2013-03-17>,
<Departure_Date: id: 2 - from: 2012-11-01 - to: 2012-12-16>,
<Departure_Date: id: 3 - from: 2012-09-16 - to: 2012-10-31>,
<Departure_Date: id: 4 - from: 2012-11-01 - to: 2012-12-16>,
<Departure_Date: id: 5 - from: 2013-01-04 - to: 2013-01-11>]


month:1
year:2013
where = '%(year)s >= YEAR(date_from) AND %(month)s >= MONTH(date_from) \
    AND %(year)s <= YEAR(date_to) AND %(month)s <= MONTH(date_to)' % \
    {'year': year, 'month': month}
Departure_Date.objects.extra(where=[where])
[<Departure_Date: id: 5 - from: 2013-01-04 - to: 2013-01-11>]

Tags: andtofromiddatemodelswhereyear
3条回答

只使用python代码的解决方案。主要思想是用python构造date_from和date_to。然后,这些日期可以与__lte__gte一起在filter中使用:

import calendar
from datetime import datetime
from django.db.models import Q

def in_month_year(month, year):
    d_fmt = "{0:>02}.{1:>02}.{2}"
    date_from = datetime.strptime(
        d_fmt.format(1, month, year), '%d.%m.%Y').date()
    last_day_of_month = calendar.monthrange(year, month)[1]
    date_to = datetime.strptime(
        d_fmt.format(last_day_of_month, month, year), '%d.%m.%Y').date()
    return Departure_Date.objects.filter(
        Q(date_from__gte=date_from, date_from__lte=date_to)
         |
        Q(date_from__lt=date_from, date_to__gte=date_from))

现在这将起作用:

>>> Departure_Date.objects.all()
[<Departure_Date: id: 1 - from: 2012-11-01 - to: 2013-03-17>,
<Departure_Date: id: 2 - from: 2012-11-01 - to: 2012-12-16>,
<Departure_Date: id: 3 - from: 2012-09-16 - to: 2012-10-31>,
<Departure_Date: id: 4 - from: 2012-11-01 - to: 2012-12-16>,
<Departure_Date: id: 5 - from: 2013-01-04 - to: 2013-01-11>]


>>> in_month_year(month=1, year=2013)
[<Departure_Date: id: 1 - from: 2012-11-01 - to: 2013-03-17>,
<Departure_Date: id: 5 - from: 2013-01-04 - to: 2013-01-11>]

检查documentation

year = 2012
month = 09
Departure_Date.objects.filter(date_from__year__gte=year,
                              date_from__month__gte=month,
                              date_to__year__lte=year,
                              date_to__month__lte=month)

使用.extra的替代方法:

where = '%(year)s >= YEAR(date_from) AND %(month)s >= MONTH(date_from) \
        AND %(year)s <= YEAR(date_to) AND %(month)s <= MONTH(date_to)' % \
        {'year': year, 'month': month}
Departure_Date.objects.extra(where=[where])

有一个特定的情况,上面的查询没有产生所需的结果。

例如:

date_from='2012-11-01'
date_to='2013-03-17'
and input is
year=2013
month=1

那么%(month)s >= MONTH(date_from)条件是错误的,因为date_from中的第1个月是<;第11个月,但年份不同,所以这里需要MySQL IF条件:

where = '%(year)s >= YEAR(date_from) AND IF(%(year)s > YEAR(date_from), \
     IF(%(month)s > MONTH(date_from), %(month)s >= MONTH(date_from), %(month)s < MONTH(date_from)), \
     IF(%(month)s < MONTH(date_from), %(month)s < MONTH(date_from), %(month)s >= MONTH(date_from))) \
     AND %(year)s <= YEAR(date_to) \
     AND %(month)s <= MONTH(date_to)' % \
     {'year': year, 'month': month}
Departure_Date.objects.extra(where=[where])

通过使用datetime.timedelta将一天添加到范围中的最后一天,可以避免由于DateTimeField/date对象比较中缺少精度而导致的“阻抗不匹配”。其工作原理如下:

import datetime

start = date(2012, 12, 11)
end = date(2012, 12, 18)
new_end = end + datetime.timedelta(days=1)

ExampleModel.objects.filter(some_datetime_field__range=[start, new_end])

相关问题 更多 >