class Operator_online(models.Model):
name = models.TextField()
role = models.TextField()
class Reservations(models.Model):
consultant_id = models.ForeignKey(Operator_online, on_delete=models.CASCADE)
voip_number = models.IntegerField()
consultants_operators = Operator_online.objects.filter(
Q(role='consultant') | Q(role='support'), status='1'
)
consultant_id_queryset = Reservations.objects.filter(
consultant_id__in=consultants_operators
).select_related('consultant_id').annotate(role=F('consultant_id__role')).values(
'consultant_id',
'consultant_id__name',
'voip_number',
'role'
)
Steel 返回与上面相同的
consultant_id_queryset
查询集值:
返回所有已创建的
Operator_online
(即 role
和 name
字段)加上现有的已分配 Reservations
(即 consultant_id
和 voip_number
)反对 在返回之前仅存在的 Reservations
已分配实例 Operator_online
。
因此,对于未建立的
Reservations
实例,其 consultant_id
字段 (foreignkey
) 与 Operator_online
返回 null
为 voip_number
和 consultant_id
consultants_operators = Operator_online.objects.filter(
Q(role='consultant') | Q(role='support'), status='1'
)
reservations_id_subquery = Reservations.objects.filter(
consultant_id=OuterRef('pk')
).values('id')[:1]
reservations_subquery = Reservations.objects.filter(
consultant_id=OuterRef('pk')
).values('voip_number')[:1]
consultant_id_queryset = consultants_operators.annotate(
reservation_consultant_id=Coalesce(Subquery(reservations_id_subquery), Value(None)),
reservation_voip_number=Coalesce(Subquery(reservations_subquery), Value(None))
).values(
'role',
'reservation_voip_number',
'reservation_consultant_id',
consultant_id__name=F('name')
)
尝试工作正常,但我看到的问题是将最后一个查询集字段命名为相同的波纹管,并抛出与响应相同的波纹管:
"The annotation 'voip_number' conflicts with a field on the model."
consultant_id_queryset = consultants_operators.annotate(
reservation_consultant_id=Coalesce(Subquery(reservations_id_subquery), Value(None)),
reservation_voip=Coalesce(Subquery(reservations_voip_subquery), Value(None))
).values(
'role',
consultant_id=F('reservation_consultant_id'),
voip_number=F('reservation_voip'),
consultant_id__name=F('name')
)