0 
class User(models.Model):
    name=CharField()


class Address(models.Model):
    user= Foreignkey(user, related_name="Addresses")
    buildingname=CharField()
    subbuildingname=CharField()
    town=CharField()
    ...

我有一个像 top 这样的模型，想提取如下列表中的数据。

{
    [
        ['USERNAME1', 'A XYZBUILDING 14 Drain St. '],
        ['USERNAME2', 'C XXXBUILDING 13 Drain St. '],
        ['USERNAME3', 'B ZZZBUILDING 12 Drain St. '],
        ...
    ]
    
}

同样作为一种解决方法，这是最接近答案的事情，但我无法完成

无需循环每个用户或

无需在额外方法的选择字段中执行原始 sql。

我想用 Django ORM 来实现这一点。

address_subquery = Address.objects.filter(user__id=F('pk')).order_by('created')
User.objects.filter(**my_custom_filters).annotate(
    subbuildingname_str=Subquery(address_subquery.values('subbuildingname')[:1], output_field=CharField()),
    street_str=Subquery(address_subquery.values('street')[:1], output_field=CharField()),
    buildingname_str=Subquery(address_subquery.values('buildingname')[:1], output_field=CharField()),
    buildingnnumber_str=Subquery(address_subquery.values('buildingnnumber')[:1], output_field=CharField()),
).annotate(
    address_text_str=Concat(
        'subbuildingname_str', Value(' '),
        'buildingname', Value(' '),
        'buildingnumber', Value(' '),
        'street_str',
        output_field=CharField(),
        default=""
    )
).values_list('name', 'address_text_str')
4

1 回答 1

1

实际上您在子查询中做错了，您必须像这样编写子查询：-

from django.db.models import OuterRef

address_subquery = Address.objects.filter(user=OuterRef('pk')).order_by('created')

您可以从这里参考https://docs.djangoproject.com/en/3.2/ref/models/expressions/#subquery-expressions

于 2021-04-18T19:44:13.720 回答