Graphene/GraphQL find specific column value - django

Question

For some reason, I can't figure out how to simply find a specific piece of data in my SQLAlchemy database.
In the graphene-python documentation it simply does this query to match the id (which is a string):
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:
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:
{
"query": "{ allBooks(first: 3) { edges { node { title } } } }"
}
However, once I try to match a specific title, it stops working. For example:
# 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\"."
I must be making a small error that I'm not seeing, but I can't figure it out. I've spent hours trying to figure this out.
Question: How can I match the title and have it return the object? What am I doing wrong?

Answer 1

Figured it out! See changes below.
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:
{
"query": "{ findBook(title: \"some book title\") { title } }"
}
Hope this helps someone in the future!