问题描述
我有两个不同的查询集,我想使两个查询集合的并发
I have two different different queryset, I want to make union of both queryset
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');
我尝试过这个功能
面对这个错误'django在两个不同的基本模型上组合查询
facing this error ' django combine queries on two different base models '
所以我已经尝试了两个其他的功能,但这些也抛出相同的异常'list'对象没有属性'model''
So i have tried two other functions but these are also throwing same exception ' list' object has no attribute 'model' '
queryset = chain(q1,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')
这里查看文件
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类型记录。
But both these functions did not return queryset type record.
我想要tbl_network(q2)的查询类型
I want queryset type of tbl_network (q2)
我如何做到这一点?
推荐答案
由于django不支持混合查询必须对应于一个模型),我建议您使用不同的方法:模型继承或FK。
As django doesn't support mixed querysets (they must correspond to just one model), I suggest you using a different approach: a model inheritance or 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))
编辑:不知道你在哪里得到你的限制字段,因为它不会出现在模型中,但是我反正把它尊重你的代码没有错误)
edit: don't know where did you get your 'restriction' field, since it does not appear in models, but i put it anyway to "respect" your code (assuming there's no error there).
编辑2 :您可以将它们与您之前尝试的方法合并,一旦查询是相同的模型(如q1 + q2)
edit 2: you can merge them with the methods you tried before, once the queries are of the same model (e.g. q1 + q2)
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