[英]Django - manager on ManyToMany relationship
I have 3 models我有 3 个模型
class Person(models.Model):
name = models.CharField(max_length=128)
class Company(models.Model):
name = models.CharField(max_length=128)
members = models.ManyToManyField (Person, through = 'Membership', related_name = 'companies')
class Membership(models.Model):
person = models.ForeignKey(Person, on_delete=models.CASCADE)
company = models.ForeignKey(Company, on_delete=models.CASCADE)
is_admin = models.BooleanField()
I can then call person.companies.all()
to get the list of companies associated with person.然后我可以调用
person.companies.all()
来获取与 person 相关的公司列表。
How do I create a manager to have the list of companies associated with person, but whose person is admin (is_admin = True)?如何创建经理以将公司列表与人员关联,但其人员是管理员(is_admin = True)?
You can filter with:您可以使用以下方式过滤:
person.companies.filter(membership__is_admin=True)
This will filter the junction table Membership
, such that it will only retrieve Company
s for which the Membership
has is_admin
set to True
.这将过滤联结表
Membership
,这样它只会检索Membership
的is_admin
设置为True
的Company
。
Another option is to retrieve this with:另一种选择是通过以下方式检索它:
Company.objects.filter(membership__is_admin=True, members=person)
You can attach this to the Person
model with:您可以将其附加到
Person
model :
class Person(models.Model):
name = models.CharField(max_length=128)
@property
def admin_companies(self):
return self.companies.filter(membership__is_admin=True)
You can create a manager like the following:您可以创建如下管理器:
managers.py
: managers.py
:
from django.db import models
class AdminCompaniesManager(models.Manager):
def get_queryset(self):
return super().get_queryset().companies.filter(membership__is_admin=True)
and then in your Person
model:然后在你的
Person
model 中:
class Person(models.Model):
name = models.CharField(max_length=128)
objects = models.Manager()
administrated_companies = AdminCompaniesManager()
Please mind the objects
manager.请注意
objects
管理器。
Now you can easily call the following in your views:现在您可以在视图中轻松调用以下内容:
my_person.administrated_companies.all()
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.