DJANGO：指的是 id

Question

这是给我带来问题的一点：错误“QuerySet”对象没有属性“地址”

        bdns = Business.objects.filter(name='slow')
        addx = bdns.address
        addr = Address.objects.get(id=addx)

我该怎么办？

我的商业模式：

class Business(models.Model): 
    phone = PhoneNumberField()
    address = models.ForeignKey(Address)
    name = models.CharField(max_length=64)

Answer 1

查询集是一个集合，即使该集合只包含一个元素。当您执行 Model.objects.filter() 时，它会返回一个查询集。

如果您想返回单个对象，请使用 Model.objects.get()。

因此，为了您的目的：

bdns = Business.objects.filter(name='slow') # returns a collection
b = dbns[0] # get the first one
the_address = b.address # the address

# or...
try:
    bdns = Business.objects.get(name='slow') # get single instance
except Business.DoesNotExist:
    bdns = None # instance didnt exist, assign None to the variable
except Business.MultipleObjectsReturned:
    bdns = None # the query returned a collection

if bdns is not None:
    the_address = bdns.address

# the_address is an instance of an Address, so no need to do the lookup with the id

print the_address.id # 7
print the_address.street # 17 John St
print the_address.city # Melbourne

Answer 2

    bdns = Business.objects.filter(name='slow')

返回一个 QuerySet （Business 对象的集合），您需要迭代以获取带有地址的每个元素。

addr = Address.objects.get(id=addx)

应该有效