django:如何在ManyToManyField(通过)相关模型中的字段上订购查询集 [英] django: How to order the queryset on a field in ManyToManyField (through) related models

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问题描述

我有这些模型

  class Region(models.Model):
name = models.CharField(max_length = 255,blank = False)

class Album(TimeStampAwareModel):
title = models.CharField(max_length = 255,blank = False)
digital_release_date = models.ManyToManyField ,through =AlbumRegionReleaseDate,related_name =release_date_albums)
published = models.BooleanField(default = False)



class AlbumRegionReleaseDate(models.Model):
album = models.ForeignKey(Album)
region = models.ForeignKey(Region)
digital_release_date = models.DateField )
class Meta:
orders =('-digital_release_date')

假设我有三个区域:欧洲,南亚和北亚



现在我想在欧洲地区获得digital_release_date的所有已发布专辑订单? p>

任何人都可以通过SQL查询告诉我怎么做?



谢谢:)

解决方案

编辑



对不起,我的错误!现在这应该有效我在家尝试了...

  Album.objects.filter(
published = True,
albumregionreleasedate__region__name ='Europe'
).order_by(
'albumregionreleasedate__digital_release_date'

这里是一些帮助未来的疑虑



希望它现在可行!


I have these models

class Region (models.Model):
    name = models.CharField (max_length = 255, blank = False)

class Album(TimeStampAwareModel):
    title = models.CharField (max_length = 255, blank = False) 
    digital_release_date = models.ManyToManyField( Region, through="AlbumRegionReleaseDate", related_name="release_date_albums")
    published = models.BooleanField (default = False)
    .
    .

class AlbumRegionReleaseDate(models.Model):
   album = models.ForeignKey (Album)
   region = models.ForeignKey (Region)
   digital_release_date = models.DateField () 
   class Meta:
    ordering = ('-digital_release_date')

Suppose i have three regions i:e Europe, South Asia and North Asia

Now i want to get all "published" albums order by "digital_release_date" in Europe region?

Can anyone please tell me how to do this by SQL query?

Thanks :)

解决方案

EDIT:

Sorry, my mistake! Now this should work. I tried it at home...

Album.objects.filter(
    published=True,
    albumregionreleasedate__region__name='Europe'
).order_by(
    'albumregionreleasedate__digital_release_date'
)

Here is some help to future doubts

Hope it works now!

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