Django在created_at上注释

Question

我想要获取Django中每天创建的记录数，但是我无法使其工作。到目前为止，我有这样的：

data = Reservation.objects\ 
     .order_by('created_at')\ 
     .extra({'dp': "date(created_at)"}) \ 
     .values('dp').annotate(count=Count('id')) 

它返回

<QuerySet [{'count': 1, 'dp': datetime.date(2017, 2, 28)}, {'count': 1, 'dp': datetime.date(2017, 2, 28)}, {'count': 1, 'dp': datetime.date(2017, 2, 28)}, {'count': 1, 'dp': datetime.date(2017, 2, 28)}, {'count': 1, 'dp': datetime.date(2017, 3, 1)}, {'count': 1, 'dp': datetime.date(2017, 3, 1)}, {'count': 1, 'dp': datetime.date(2017, 3, 1)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, {'count': 1, 'dp': datetime.date(2017, 3, 2)}, '...(remaining elements truncated)...']> 

我怎么能算dp记录在一起，这样我会得到：

<QuerySet [{'count': 4, 'dp': datetime.date(2017, 2, 28)}{'count': 3, 'dp': datetime.date(2017, 3, 1)},.. 

Answer 1

这应该是最后一个：

.order_by('dp') 

Answer 2

你有任何元订购模型预订？否则，查询应该只是正常工作