我想创建两个现有类型(FirstType 和 SecondType)的 UnionType(graphene.Union) 并能够解析此联合类型的查询。
class FirstType(DjangoObjectType):
class Meta:
model = FirstModel
class SecondType(DjangoObjectType):
class Meta:
model = SecondModel
class UnionType(graphene.Union):
class Meta:
types = (FirstType, SecondType)
因此,使用此模式,我想使用某个列表 [pks] 中的 pk 查询 FirstType 和 SecondType 中的所有对象
query {
all_items(pks: [1,2,5,7]){
... on FirstType{
pk,
color,
}
... on SecondType{
pk,
size,
}
}
}
来自 FirstType 的 PK 通常不在 SecondType 中。
我尝试了下面的方法
def resolve_items(root, info, ids):
queryset1 = FirstModel.objects.filter(id__in=pks)
queryset2 = SecondModel.objects.filter(id__in=pks)
return queryset1 | queryset2
但它给出了一个错误:“无法组合两个不同基础模型上的查询。”
我期望查询得到以下答复:
{ 'data':
{'all_items':[
{'pk': 1,
'color': blue
},
{'pk': 2,
'size': 50.0
},
...
]}
}
那么解析器应该是什么样子?
关于联合类型的石墨烯文档非常稀疏。这是如何正确执行此操作的工作示例:
from graphene import ObjectType, Field, List, String, Int, Union
mock_data = {
"episode": 3,
"characters": [
{
"type": "Droid",
"name": "R2-D2",
"primaryFunction": "Astromech"
},
{
"type": "Human",
"name": "Luke Skywalker",
"homePlanet": "Tatooine"
},
{
"type": "Starship",
"name": "Millennium Falcon",
"length": 35
}
]
}
class Human(ObjectType):
name = String()
homePlanet = String()
class Droid(ObjectType):
name = String()
primaryFunction = String()
class Starship(ObjectType):
name = String()
length = Int()
class Character(Union):
class Meta:
types = (Human, Droid, Starship)
@classmethod
def resolve_type(cls, instance, info):
if instance["type"] == "Human":
return Human
if instance["type"] == "Droid":
return Droid
if instance["type"] == "Starship":
return Starship
class RootQuery(ObjectType):
result = Field(SearchResult)
def resolve_result(_, info):
return mock_data
然后,对于像
这样的查询 query Humans {
result {
episode
characters {
... on Droid {
name
}
... on Starship {
name
}
... on Human {
name
}
}
}
}
它返回正确的结果。
好吧,所以我太专注于合并查询集,而没有注意到我可以简单地返回一个列表。
所以这里的解决方案给了我我正在寻找的答案:
def resolve_items(root, info, ids):
items = []
queryset1 = FirstModel.objects.filter(id__in=pks)
items.extend(queryset1)
queryset2 = SecondModel.objects.filter(id__in=pks)
items.extend(queryset2)
return items