graphql - 使用 GraphQL、Graphene 和 Python 从查询中返回任何数据
问题描述
我收到以下错误:
{
"errors": [
{
"message": "Unknown argument \"project_id\" on field" +
\"get_project_detail_summary\" of type \"Query\".",
"locations": [
{
"line": 2,
"column": 30
}
]
}
]
}
使用以下查询:
query GetProjectDetailSummary($project_id: Int) {
get_project_detail_summary(project_id: $project_id) {
comments {
... on ManagerCommentNode {
id
text
created
}
... on VendorCommentNode {
id
text
created
}
... on TenantCommentNode {
id
text
created
}
}
}
}
使用以下后端代码,我怎样才能到达断点?,或者我如何发回给定数字的自定义数据?:
class CommentsUnion(graphene.types.union.Union):
class Meta:
name = 'CommentsUnion'
types = (ManagerCommentNode, VendorCommentNode, TenantCommentNode, )
class ProjectSummaryInput(graphene.InputObjectType):
project_id = graphene.Int()
class ProjectSummaryNode(graphene.ObjectType):
Input = ProjectSummaryInput
project_id = graphene.Int()
comments = graphene.List(CommentsUnion)
@classmethod
def resolve_comments(self, *args, **kwargs):
import pdb;pdb.set_trace()
return ProjectSummary.select_related('comments').objects.filter(comments__created__lt=dt)
class Query(graphene.ObjectType):
get_project_detail_summary = Field(ProjectSummaryNode)
解决方案
关于错误。
请务必在 for 中添加一个 kwarg(例如project_id
,在此示例中,这是“字段上的未知参数”错误的原因graphene.Field
)get_project_detail_summary
。
像这样:
class Query(graphene.ObjectType):
get_project_detail_summary = Field(ProjectSummaryNode, # see below for example
project_id=graphene.Int() # kwarg here
)
def resolve_get_project_detail_summary(self, info, **kwargs):
return ProjectSummary.objects.get(id=kwargs.get('project_id'))
关于返回任何数据。
这是一种方式(返回 a graphene.String
),但它通过将所有内容放入字符串中来取消类型化响应:
from django.core.serializers.json import DjangoJSONEncoder
class ProjectSummaryRecentUpdatesNode(graphene.ObjectType):
Input = ProjectSummaryInput
recent_updates = graphene.String()
def resolve_recent_updates(self, resolve, **kwargs):
instance = Project.objects.get(id=resolve.variable_values.get("project_id"))
things = instance.things.all()
# these are all from different models, and the list is a bit longer than this.
querysets = (
("scheduled", get_scheduled(things, resolve, **kwargs)),
("completed", get_completed(things, resolve, **kwargs)),
("invoices", get_invoices(things, resolve, **kwargs)),
("expenditures", get_expenditures(things, resolve, **kwargs)),
("comments", get_comments(things, resolve, **kwargs)),
("files", get_files(things, resolve, **kwargs)),
)
recent_updates = []
for update_type, qs in querysets:
for item in qs:
item.update(
{
"recent_update_type": update_type
}
)
recent_updates.append(item)
return json.dumps(recent_updates, cls=DjangoJSONEncoder)
而在前端,import { Query } from "react-apollo";
我们可以使用一个元素来JSON.parse
字段......其中包含“任何”(json序列化)数据:
<Query
query={GET_PROJECT_DETAIL_SUMMARY_RECENT_UPDATES}
fetchPolicy="network-only"
variables={{ project_id: this.props.projectId }}
>
{({ loading, error, data }: QueryResult) => {
if (
data &&
data.get_project_detail_summary_recent_updates &&
data.get_project_detail_summary_recent_updates.recent_updates
) {
console.log(JSON.parse(data.get_project_detail_summary_recent_updates.recent_updates))
}
}}
</Query>
边注:
如果没有大量数据类型列表,则创建一个Union
类似的对象,该对象具有不同模型所需的所有字段,或者一个实际的对象Union
,这似乎是正确的方法,因为这样类型不会丢失:
class ProjectSummaryNode(graphene.ObjectType):
# from FileNode graphene.ObjectType class
file__id = graphene.Int()
file__brief_description = graphene.String()
file_count = graphene.Int()
last_file_created = graphene.String()
last_file = graphene.String()
# from UploaderNode graphene.ObjectType class
uploader__first_name = graphene.String()
uploader__last_name = graphene.String()
# from CommentNode graphene.ObjectType class
comment = graphene.String()
class Meta:
name = "ProjectSummaryNode"
# example of Union, the above fields would be commented out, as they are part of
# the different graphene.ObjectType classes, and this line below would be uncommented
# types = ( FileNode, UploaderNode, CommentNode, )
仍然愿意接受有关更好方法的建议。