如何使用graphql从mongodb查询日期？

const { graphql, buildSchema } = require('graphql');
const { MongoClient } = require('mongodb');

// 定义GraphQL Schema
const schema = buildSchema(`
  type Query {
    getDates: [Date]
  }

  type Date {
    id: ID
    value: String
  }
`);

// 连接MongoDB数据库
const url = 'mongodb://localhost:27017';
const dbName = 'mydb';

// 编写GraphQL解析器
const root = {
  getDates: async () => {
    const client = new MongoClient(url);
    await client.connect();
    const db = client.db(dbName);
    const collection = db.collection('dates');
    
    // 查询日期数据
    const dates = await collection.find().toArray();
    
    client.close();
    
    return dates;
  }
};

// 执行GraphQL查询
const query = `
  query {
    getDates {
      id
      value
    }
  }
`;

graphql(schema, query, root)
  .then(result => console.log(result))
  .catch(error => console.error(error));