使用async和await检查电子邮件是否已存在于Mongo Atlas DB中

// 引入MongoDB驱动程序
const MongoClient = require('mongodb').MongoClient;

// 连接Mongo Atlas数据库
const uri = 'mongodb+srv://<username>:<password>@<cluster-url>/<database>?retryWrites=true&w=majority';
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });

// 检查电子邮件是否存在的函数
async function checkEmailExists(email) {
  try {
    // 连接数据库
    await client.connect();

    // 获取数据库和集合
    const db = client.db('<database>');
    const collection = db.collection('<collection>');

    // 查询电子邮件是否存在
    const result = await collection.findOne({ email: email });

    // 返回结果
    return result !== null;
  } catch (error) {
    console.error('Error occurred while checking email:', error);
    throw error;
  } finally {
    // 断开数据库连接
    await client.close();
  }
}

// 使用示例
const email = 'example@example.com';
checkEmailExists(email)
  .then(exists => {
    if (exists) {
      console.log('Email exists in the database.');
    } else {
      console.log('Email does not exist in the database.');
    }
  })
  .catch(error => {
    console.error('Error occurred:', error);
  });