Query
is a class within the sqlalchemy.orm.query
module of the SQLAlchemy project.
QueryContext
is another callable from the sqlalchemy.orm.query
package with code examples.
graphene-sqlalchemy (project documentation and PyPI package information) is a SQLAlchemy integration for Graphene, which makes it easier to build GraphQL-based APIs into Python web applications. The package allows you to subclass SQLAlchemy classes and build queries around them with custom code to match the backend queries with the GraphQL-based request queries. The project is provided as open source under the MIT license.
graphene-sqlalchemy / graphene_sqlalchemy / fields.py
# fields.py
import warnings
from functools import partial
import six
from promise import Promise, is_thenable
from sqlalchemy.orm.query import Query
from graphene import NonNull
from graphene.relay import Connection, ConnectionField
from graphene.relay.connection import PageInfo
from graphql_relay.connection.arrayconnection import connection_from_list_slice
from .batching import get_batch_resolver
from .utils import get_query
class UnsortedSQLAlchemyConnectionField(ConnectionField):
@property
def type(self):
from .types import SQLAlchemyObjectType
_type = super(ConnectionField, self).type
nullable_type = get_nullable_type(_type)
if issubclass(nullable_type, Connection):
return _type
assert issubclass(nullable_type, SQLAlchemyObjectType), (
"SQLALchemyConnectionField only accepts SQLAlchemyObjectType types, not {}"
).format(nullable_type.__name__)
assert (
nullable_type.connection
), "The type {} doesn't have a connection".format(
nullable_type.__name__
)
assert _type == nullable_type, (
"Passing a SQLAlchemyObjectType instance is deprecated. "
"Pass the connection type instead accessible via SQLAlchemyObjectType.connection"
)
return nullable_type.connection
@property
def model(self):
return get_nullable_type(self.type)._meta.node._meta.model
@classmethod
def get_query(cls, model, info, **args):
return get_query(model, info.context)
@classmethod
def resolve_connection(cls, connection_type, model, info, args, resolved):
if resolved is None:
resolved = cls.get_query(model, info, **args)
if isinstance(resolved, Query):
_len = resolved.count()
else:
_len = len(resolved)
connection = connection_from_list_slice(
resolved,
args,
slice_start=0,
list_length=_len,
list_slice_length=_len,
connection_type=connection_type,
pageinfo_type=PageInfo,
edge_type=connection_type.Edge,
)
connection.iterable = resolved
connection.length = _len
return connection
@classmethod
def connection_resolver(cls, resolver, connection_type, model, root, info, **args):
resolved = resolver(root, info, **args)
on_resolve = partial(cls.resolve_connection, connection_type, model, info, args)
if is_thenable(resolved):
return Promise.resolve(resolved).then(on_resolve)
## ... source file continues with no further Query examples...