我需要得到过去几天创建的对象列表,按天分组,以便在图表中显示数据。你知道吗
我有这个模型:
class Model(Base):
...
created = DateTimeField(default=timezone.now(), editable=False)
...
现在我要做的是:
Model.objects.filter(
created__date__lte=today,
created__date__gte=today-delta
).values('created').annotate(count=Count('id'))
但是,我得到以下查询集:
<SoftDeletableQuerySet [{'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 208157, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 297617, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 385555, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 474287, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 507464, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 552092, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 585314, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 618656, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 652501, tzinfo=<UTC>), 'count': 1}, {'created': datetime.datetime(2018, 10, 15, 13, 5, 35, 696849, tzinfo=<UTC>), 'count': 1}]>
如您所见,对象是按创建日期分组的,但是这个字段是DateTimeField
,而不是DateField
,因此,以毫秒为单位分组。你知道吗
我试着这么做:
Model.objects.filter(
created__date__lte=today,
created__date__gte=today-delta
).values('created__date').annotate(count=Count('id'))
但我得到以下错误:
FieldError: Cannot resolve keyword 'date' into field. Join on 'created' not permitted.
我认为我所需要的是非常普遍的,而且一定有某种枯燥的方法来做到这一点。你知道吗
您可以使用带有^{} [Django-doc]表达式的
.annotate(..)
来截断到日期:.order_by
是必要的,因为否则您不会“强制”Django使用GROUP BY
,因此Count('id')
将不包含该特定日期的项目总数。你知道吗相关问题 更多 >
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