Python Django queryset过滤器适用于过去和未来的最新版本 上下文
我有如下型号的Python Django queryset过滤器适用于过去和未来的最新版本 上下文,python,django,Python,Django,我有如下型号的ContentBuild&ContentBuildDeviceGroupLink: # models.py class ContentBuild(models.Model): content_build_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True) class ContentBuildDeviceGroupLink(models.
ContentBuild
&ContentBuildDeviceGroupLink
:
# models.py
class ContentBuild(models.Model):
content_build_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
class ContentBuildDeviceGroupLink(models.Model):
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
content_build_uuid = models.ForeignKey(ContentBuild, on_delete=models.CASCADE, related_name='content_build_deploy')
group_uuid = models.ForeignKey(DeviceGroup, on_delete=models.CASCADE)
preload_date = UnixDateTimeField()
release_date = UnixDateTimeField()
in_future = Q(release_date__gte=timezone.now())
recent_past = Q(release_date__lt=timezone.now()).order_by('-release_date')[0]
ContentBuildDeviceGroupLink.objects
.filter(in_future & recent_past)
from django.db.models import Subquery, F
recent_dates = ContentBuildDeviceGroupLink.objects.filter(
release_date__lte=timezone.now()
).order_by('-release_date').values('release_date')
ContentBuildDeviceGroupLink.objects.annotate(
start_time=Subquery(recent_dates[:1])
).filter(release_date__gte=F('start_time'))
目标
我想返回过去带有发布日期的最新ContentBuildDeviceGroupLink
对象,以及将来带有发布日期的所有ContentBuildDeviceGroupLink
对象
我试过的
我试着像这样使用Q对象
:
# models.py
class ContentBuild(models.Model):
content_build_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
class ContentBuildDeviceGroupLink(models.Model):
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
content_build_uuid = models.ForeignKey(ContentBuild, on_delete=models.CASCADE, related_name='content_build_deploy')
group_uuid = models.ForeignKey(DeviceGroup, on_delete=models.CASCADE)
preload_date = UnixDateTimeField()
release_date = UnixDateTimeField()
in_future = Q(release_date__gte=timezone.now())
recent_past = Q(release_date__lt=timezone.now()).order_by('-release_date')[0]
ContentBuildDeviceGroupLink.objects
.filter(in_future & recent_past)
from django.db.models import Subquery, F
recent_dates = ContentBuildDeviceGroupLink.objects.filter(
release_date__lte=timezone.now()
).order_by('-release_date').values('release_date')
ContentBuildDeviceGroupLink.objects.annotate(
start_time=Subquery(recent_dates[:1])
).filter(release_date__gte=F('start_time'))
这不起作用并引发错误:
'datetime.datetime' object has no attribute 'order_by'
如何筛选最近具有release\u date
的对象以及将来具有release\u date
的所有对象
编辑
我改变了我的方法,所以我首先获取具有最近过去的对象,然后过滤所有大于或等于此日期的对象。但是,当只有一个ContentBuild
时,下面的查询集可以正常工作,但当有多个相关的ContentBuild
时,会返回所有旧对象
recent_past = ContentBuildDeviceGroupLink.objects
.filter(release_date__lte=timezone.now()).order_by('release_date').first()
ContentBuildDeviceGroupLink.objects.filter(release_date__gt=recent_past.release_date)
您可以使用
order\u by
而不是查询集。试试这个
in_future = Q(release_date__gte=timezone.now())
recent_past = Q(release_date__lt=timezone.now())
ContentBuildDeviceGroupLink.objects.filter(
in_future & recent_past
).order_by('-release_date').first()
您的第二次尝试很接近,但有两个问题:
第一个
对象,因此这是发布日期最早的人,而不是最近的人gt
而不是gte
似乎有点可疑。。。当只有一个ContentBuild
# models.py
class ContentBuild(models.Model):
content_build_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
class ContentBuildDeviceGroupLink(models.Model):
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
content_build_uuid = models.ForeignKey(ContentBuild, on_delete=models.CASCADE, related_name='content_build_deploy')
group_uuid = models.ForeignKey(DeviceGroup, on_delete=models.CASCADE)
preload_date = UnixDateTimeField()
release_date = UnixDateTimeField()
in_future = Q(release_date__gte=timezone.now())
recent_past = Q(release_date__lt=timezone.now()).order_by('-release_date')[0]
ContentBuildDeviceGroupLink.objects
.filter(in_future & recent_past)
from django.db.models import Subquery, F
recent_dates = ContentBuildDeviceGroupLink.objects.filter(
release_date__lte=timezone.now()
).order_by('-release_date').values('release_date')
ContentBuildDeviceGroupLink.objects.annotate(
start_time=Subquery(recent_dates[:1])
).filter(release_date__gte=F('start_time'))
也许有一种更聪明的方法,但似乎有效。谢谢您的回复。这将导致一个空查询集。可能是因为
最近的\u pass
包含所有过去的对象。谢谢您的帮助。我正在运行Django 2.2。您的第一个解决方案将Q对象作为错误抛出,该对象不可调用。你的第二个解决方案很有魅力!真奇怪。希望我有一个2.2的项目,我可以尝试它。不管怎样,很高兴另一个人工作了。