django模型外键查询器选择相关字段 [英] django model foreign key queryset selecting related fields
问题描述
我正在尝试从DJango中的两个相关表的加入中选择,如下所示。但是我不能得到另一个表的名称
。
I am trying to select from the join of the two related tables in DJango as shown below. But I am not able get the field name
of the other table.
在SQL中,我们可以写: p>
In SQL we can write:
select person.phonenumber,membership.* from membership where person=name ;
这将显示所有成员资格
phonenumber
,但在Django中它会抛出错误:
This displays all the membership
fields along with phonenumber
, but in Django it throws error:
无法解析关键字'phonenumber'进入字段
Cannot resolve keyword 'phonenumber' into field
我甚至尝试使用 select_related
但没有用。我做错了吗?
I have even tried with select_related
but no use. Am I doing anything wrong?
model.py:
from django.db import models
# Create your models here.
class Person(models.Model):
name = models.CharField(primary_key=True,max_length=128)
phonenumber = models.CharField(max_length=128)
city = models.CharField(max_length=128)
def __unicode__(self):
return self.name
class Membership(models.Model):
person = models.ForeignKey(Person)
date_joined = models.DateField()
invite_reason = models.CharField(max_length=64)
>>> print m.query
SELECT `myapp_membership`.`id`, `myapp_membership`.`person_id`, `myapp_membership`.`date_joined`, `myapp_membership`.`invite_reason` FROM `myapp_membership` WHERE `myapp_membership`.`person_id` = x
>>> m=Membership.objects.filter(person__name='x').select_related()
>>> print m.query
SELECT `myapp_membership`.`id`, `myapp_membership`.`person_id`, `myapp_membership`.`date_joined`, `myapp_membership`.`invite_reason`, `myapp_person`.`name`, `myapp_person`.`phonenumber`, `myapp_person`.`city` FROM `myapp_membership` INNER JOIN `myapp_person` ON (`myapp_membership`.`person_id` = `myapp_person`.`name`) WHERE `myapp_membership`.`person_id` = x
>>> m=Membership.objects.filter(person__name='x').values('person','phonenumber').select_related()
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/usr/local/lib/python2.6/dist-packages/Django-1.2.4-py2.6.egg/django/db/models/query.py", line 510, in values
return self._clone(klass=ValuesQuerySet, setup=True, _fields=fields)
File "/usr/local/lib/python2.6/dist-packages/Django-1.2.4-py2.6.egg/django/db/models/query.py", line 766, in _clone
c._setup_query()
File "/usr/local/lib/python2.6/dist-packages/Django-1.2.4-py2.6.egg/django/db/models/query.py", line 889, in _setup_query
self.query.add_fields(self.field_names, False)
File "/usr/local/lib/python2.6/dist-packages/Django-1.2.4-py2.6.egg/django/db/models/sql/query.py", line 1537, in add_fields
"Choices are: %s" % (name, ", ".join(names)))
FieldError: Cannot resolve keyword 'phonenumber' into field. Choices are: date_joined, id, invite_reason, person
推荐答案
code> phonenumber 是个人
上的一个字段,因此您需要传入 person__phonenumber
phonenumber
is a field on person
, so you need to pass in person__phonenumber
m=Membership.objects.filter(person__name='x').values('person','person__phonenumber').
这篇关于django模型外键查询器选择相关字段的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!