MongoDB+Mongoose+GraphQL or just MongoDB+GraphQL ref http://stackoverflow.com/questions/37237673/do-i-need-mongoose-with-graphql

MongoDB+GraphQL

resolve: () => {
  return new Promise((resolve, reject) => {
    db.collection('todos').find({}).toArray((err, todos) => {
      if (err) reject(err)
      else resolve(todos)
    })
  })
}

MongoDB+Mongoose+GraphQL

// ref https://www.compose.com/articles/using-graphql-with-mongodb/
var QueryType = new GraphQLObjectType({  
  name: 'Query',
  fields: () => ({
    todos: {
      type: new GraphQLList(TodoType),
      resolve: () => {
        return new Promise((resolve, reject) => {
          TODO.find((err, todos) => {
            if (err) reject(err)
            else resolve(todos)
          })
        })
      }
    }
  })
})