[英]Graphene/GraphQL find specific column value
For some reason, I can't figure out how to simply find a specific piece of data in my SQLAlchemy database. 由于某些原因,我无法弄清楚如何在我的SQLAlchemy数据库中简单地查找特定的数据。
In the graphene-python documentation it simply does this query to match the id (which is a string): 在graphene-python文档中,它只是简单地执行此查询以匹配id(它是一个字符串):
book(id: "Qm9vazow") {
id
title
}
Now here's my Flask-Graphene-SQLAlchemy code for my BookSchema and I want to find a specific title instead of an ID: 现在,这是我的BookSchema的Flask-Graphene-SQLAlchemy代码,我想找到一个特定的标题而不是ID:
class BookModel(db.Model):
__table__ = db.Model.metadata.tables['books_book']
# Schema Object
class BookSchema(SQLAlchemyObjectType):
class Meta:
model = BookModel
interfaces = (relay.Node, )
# Connection
class BookConnection(relay.Connection):
class Meta:
node = BookSchema
# GraphQL query
class Query(graphene.ObjectType):
node = relay.Node.Field()
allBooks = SQLAlchemyConnectionField(BookConnection)
schema = graphene.Schema(query=Query, types=[BookSchema])
When I run this query, everything is fine and returns 3 book titles: 当我运行此查询时,一切都很好,并返回3个书名:
{
"query": "{ allBooks(first: 3) { edges { node { title } } } }"
}
However, once I try to match a specific title, it stops working. 但是,一旦我尝试匹配特定的标题,它将停止工作。 For example:
例如:
# I tried all these queries, none worked
1. { allBooks(title: \"some book title\") { edges { node { title } } } }
2. { allBooks(title: \"some book title\") { title }
3. { allBooks(title: 'some book title') { edges { node { title } } } }
The error: "Unknown argument \\"title\\" on field \\"allBooks\\" of type \\"Query\\"."
错误:
"Unknown argument \\"title\\" on field \\"allBooks\\" of type \\"Query\\"."
I must be making a small error that I'm not seeing, but I can't figure it out. 我必须犯一个我没有看到的小错误,但我无法弄清楚。 I've spent hours trying to figure this out.
我花了几个小时试图弄清楚这一点。
Question: How can I match the title and have it return the object? 问题:如何匹配标题并使它返回对象? What am I doing wrong?
我究竟做错了什么?
Figured it out! 弄清楚了! See changes below.
请参阅下面的更改。
class Query(graphene.ObjectType):
node = relay.Node.Field()
all_books = SQLAlchemyConnectionField(BookConnection)
# Added this
find_book = graphene.Field(BookSchema, title = graphene.String())
def resolve_find_book(self, info, title):
query = BookSchema.get_query(info)
return query.filter(BookModel.title == title).first()
And my GraphQL query looks like this: 我的GraphQL查询看起来像这样:
{
"query": "{ findBook(title: \"some book title\") { title } }"
}
Hope this helps someone in the future! 希望这对以后的人有所帮助!
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