Django在两个不同的基本模型上组合查询

Question

我有两个不同的查询集，我想对这两个查询集进行并集

 q1 = tbl_nt_123.objects.values_list('id', 'value', 'geometry').filter(restriction='height')
        .exclude(condition_id__in=tbl_conditions.objects.filter(version_id=5).values_list('condition_id',flat=True))
 q2 = tbl_network.objects.all().filter(Q(name="height"), Q(state_id=1) | Q(state_id=2)).values_list('id', 'value', 'geometry');

我已经尝试了这个函数

queryset = (q1) | (q2)

遇到错误' django combine queries on two different base models '

所以我尝试了另外两个函数，但这些也抛出相同的异常'列表'对象没有属性'模型' '

queryset = list(q1) + list(q2)

queryset = chain(q1, q2)

从这里更新我的问题

class tbl_nt_123(models.Model):
    condition_id = models.IntegerField(blank=True, null=True)
    value = models.FloatField(blank=True, null=True)
    geometry = models.GeometryField(blank=True, null=True)
    class Meta:
        db_table = u'tbl_nt_123'
class tbl_conditions(models.Model):
    condition_id = models.IntegerField()
    version_id = models.ForeignKey(LookupNavteqversion)
    class Meta:
        db_table = u'tbl_conditions'

class tbl_network(models.Model):
    name = models.CharField(max_length=50, blank=True)
    value = models.FloatField()
    state_id = models.IntegerField(null=True, blank=True)
    geometry = models.GeometryField(null=True, blank=True)
    objects = models.GeoManager()
    class Meta:
        db_table = u'tbl_network'
    def __unicode__(self):
        return '%s' % self.name
class tbl_networkSerializer(serializers.GeoModelSerializer):
    class Meta:
        model = tbl_network
        fields = ('id', 'value', 'geometry')

此处查看文件

   class NetworkViewSet(viewsets.ModelViewSet):
      q1 = tbl_nt_123.objects.values_list('id', 'value', 'geometry').filter(restriction='height')
            .exclude(condition_id__in=tbl_conditions.objects.filter(version_id=5).values_list('condition_id',flat=True))
     q2 = tbl_network.objects.all().filter(Q(name="height"), Q(state_id=1) | Q(state_id=2)).values_list('id', 'value', 'geometry');
     queryset = list(chain(q1, q2))
     serializer_class = tbl_networkSerializer

但是这两个函数都没有返回查询集类型的记录。

我想要查询集类型的tbl_network (q2)

我该怎么做?

Answer 1

由于django不支持混合查询集(它们必须只对应一个模型)，我建议您使用不同的方法:模型继承或FK。

class MyGeometry(models.Model):
    value = ...
    geometry = ...
class tbl_nt_123(MyGeometry):
    condition_id = models.IntegerField(blank=True, null=True)
    value = models.FloatField(blank=True, null=True)
    geometry = models.GeometryField(blank=True, null=True)
class tbl_network(MyGeometry):
    name = models.CharField(max_length=50, blank=True)
    state_id = models.IntegerField(null=True, blank=True)
    objects = models.GeoManager()
...
#you should also rewrite your queries and then merge them.
#remember that inheritance let's you access parent_links and children_links
#between models.
#your query 1 should be like this one below, and a similar approach for query2.
#since they will be of the same type, you can merge them. Later, you can access
#their children links ('tbl_nt_123' and 'tbl_network), being aware that upon non-existance those links will throw DoesNotExist, upon model iteration.
q1 = MyGeometry.objects.values_list('id', 'value', 'geometry').select_related('tbl_nt_123').filter(tbl_nt_123__restriction='height')
.exclude(condition_id__in=tbl_conditions.objects.filter(version_id=5).values_list('condition_id',flat=True))

edit:不知道你从哪里得到你的"限制"字段，因为它没有出现在模型中，但我把它放在"尊重"你的代码(假设没有错误)。

edit 2:你可以合并他们与你之前尝试的方法，一旦查询是相同的模型(例如q1 + q2)