Connect to MongoDB连接到MongoDB

Create your Node.js Application创建Node.js应用程序

Create a file to contain your application called index.js in your node_quickstart project directory.在node_quickstart项目目录中创建一个名为index.js的文件来包含应用程序。

Copy and paste the following code into the index.js file:将以下代码复制并粘贴到index.js文件中：

const { MongoClient } = require("mongodb");

// Replace the uri string with your connection string.将uri字符串替换为连接字符串。
const uri = "<connection string uri>";

const client = new MongoClient(uri);

async function run() {
  try {
    const database = client.db('sample_mflix');
    const movies = database.collection('movies');

    // Query for a movie that has the title 'Back to the Future'查询标题为“回到未来”的电影
    const query = { title: 'Back to the Future' };
    const movie = await movies.findOne(query);

    console.log(movie);
  } finally {
    // Ensures that the client will close when you finish/error确保客户端在您完成/出错时关闭
    await client.close();
  }
}
run().catch(console.dir);

Assign the Connection String指定连接字符串

Replace the <connection string uri> placeholder with the connection string that you copied from the Create a Connection String step of this guide.将<connection string uri>占位符替换为从本指南的创建连接字符串步骤中复制的连接字符串。

Run your Node.js Application运行Node.js应用程序

In your shell, run the following command to start this application:在您的shell中，运行以下命令来启动此应用程序：

node index.js

You should see the details of the retrieved movie document in the command line output:您应该在命令行输出中看到检索到的电影文档的详细信息：

{
  _id: ...,
  plot: 'A young man is accidentally sent 30 years into the past...',
  genres: [ 'Adventure', 'Comedy', 'Sci-Fi' ],
  ...
  title: 'Back to the Future',
  ...
}

If you encounter an error or see no output, check whether you specified the proper connection string in the index.js file, and that you loaded the sample data.如果遇到错误或没有输出，请检查是否在index.js文件中指定了正确的连接字符串，以及是否加载了示例数据。