我有一个应用程序,有许多投资者投资同一轮,属于公司,如下所示。但是,当用户(投资者)登录时,我只希望他能够看到HIS投资。
{
"id": 1,
"name": "Technology Company",
"rounds": [
{
"id": 1,
"kind": "priced round",
"company": 1,
"investments": [
{
"id": 1,
"investor": 1,
"round": 1,
"size": 118000,
},
{
"id": 2,
"investor": 2,
"round": 1,
"size": 183000,
},
]
}
]
},
目前,我的视图集扩展get_queryset
:
class CompanyViewSet(viewsets.ModelViewSet):
def get_queryset(self):
user = self.request.user
investor = Investor.objects.get(user=user)
companies = Company.objects.filter(rounds__investments__investor=investor)
return companies
它检索属于投资者的投资,但是当它再次获得这些投资以获取回合时,它会抓住所有投资者的回合。
我怎么写这个只是为了向投资者显示下面的投资?
以下是我的模特:
class Company(models.Model):
name = models.CharField(max_length=100)
class Round(PolymorphicModel):
company = models.ForeignKey(Company, related_name='rounds', blank=True, null=True)
class Investment(PolymorphicModel):
investor = models.ForeignKey(Investor, related_name='investor')
size = models.BigIntegerField(default=0)
答案 0 :(得分:2)
您对所发生情况的描述尚不清楚。什么"何时再次进行这些投资"意思?无论如何,我猜你需要做的是使用.prefetch_related
和Prefetch对象。
from django.db.models import Prefetch
class CompanyViewSet(viewsets.ModelViewSet):
def get_queryset(self):
user = self.request.user
investor = Investor.objects.get(user=user)
companies = Company.objects.filter(
rounds__investments__investor_id=investor.id
).prefetch_related(Prefetch(
'rounds__investments',
queryset=Investment.objects.filter(
investor_id=investor.pk,
),
))
return companies
我还没有对这个代码段进行过测试,但它应该会给你一个指向正确方向的指针。我还优化了investor
查找以仅检查id,这将为您节省不必要的间接。