我想從如下所示的DJango中的兩個相關表的聯接中進行選擇。但我無法獲得另一個表的字段name
。django模型外鍵查詢集選擇相關字段
在SQL我們可以這樣寫:
select person.phonenumber,membership.* from membership where person=name ;
這顯示所有membership
領域與phonenumber
一起,但在Django它拋出錯誤:
Cannot resolve keyword 'phonenumber' into field
我甚至用select_related
,但沒有用試過。我做錯了什麼?
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
哈哈,我忘了把person__作爲關係,謝謝一噸yuji – sush 2011-03-21 16:38:43
@Yuji'Tomita'Tomita如果我需要再加入一個值,該怎麼辦?例如,如果Person表中包含我想要查找的地址表Company的外鍵。 我認爲我需要添加值:'person__company__address'。但這對我不起作用。你知道我該怎麼辦? – GileBrt 2018-01-22 12:28:10
@GileBrt這將工作,如果你有一個FK的'Membership'模型與FK到'Company'的'Person'有一個名爲'address'的字段。你可能有一個稍微不同的模型,所以我建議你發佈一個新問題。 – 2018-01-24 07:03:41