mongoengine connection and multiple databases

问题

I have 2 databases I want to query from, but I only get results from one. I'm using mongoengine with python and graphene (it's my first time). I've exhausted my search and I don't understand how I can resolve this issue. Here is my code:

import graphene
from mongoengine import Document, connect
from mongoengine.context_managers import switch_collection
from mongoengine.fields import (
    StringField,
    UUIDField,
    IntField,
    FloatField,
    BooleanField,
)
from graphene_mongo import MongoengineObjectType
from mongoengine.connection import disconnect


class UserModel(Document):
    meta = {"collection": "users"}

    userID = UUIDField()
    first_name = StringField()
    last_name = StringField()


class Users(MongoengineObjectType):
    class Meta:
        model = UserModel


class UsersQuery(graphene.ObjectType):
    users = graphene.List(Users)
    user = graphene.Field(Users, userID=graphene.UUID())

    def resolve_users(self, info):
        db = connect("users")
        users = list(UserModel.objects.all())
        db.close()
        return users

    def resolve_user(self, info, userID):
        return UserModel.objects(userID=userID).first()


users_schema = graphene.Schema(query=UsersQuery)

import graphene
from mongoengine import Document, connect
from mongoengine.fields import StringField, UUIDField
from graphene_mongo import MongoengineObjectType
from mongoengine.connection import disconnect


class Workout(Document):
    meta = {"collection": "workouts"}

    workoutID = UUIDField()
    workout_label = StringField()


class Workouts(MongoengineObjectType):
    class Meta:
        model = Workout


class Query(graphene.ObjectType):
    workouts = graphene.List(Workouts)
    workout = graphene.Field(Workouts, workoutID=graphene.UUID())

    def resolve_workouts(self, info):
        db = connect("workouts")
        wks = list(Workout.objects.all())
        db.close()
        return wks

    def resolve_workout(self, info, workoutID):
        return Workout.objects(workoutID=workoutID).first()


workouts_schema = graphene.Schema(query=Query)

Now when I have my python server up, mongod running I can hit the /workouts and it will return the array I need. But /users will not return the results.

I get no errors, nothing is wrong with my graphene query.

I can only get one of the queries to work at once.

I have tried using alias, not closing the connections, declaring the connect at the top level even before class UserModel or Workout.

回答1:

If each of your model is bound to a different database. You should use something like this (cfr docs):

connect('workouts', alias='dbworkouts')  # init a connection to database named "workouts" and register it under alias "dbworkouts"
connect('users', alias='dbusers')    

class Workout(Document):
    meta = {"db_alias": "dbworkouts"}
    workoutID = UUIDField()
    ...

class UserModel(Document):
    meta = {"db_alias": "dbusers"}
    userID = UUIDField()
    ...

来源：https://stackoverflow.com/questions/55584024/mongoengine-connection-and-multiple-databases

标签

mongodb

mongoengine

graphene-python