Get Started with the Node.js Driver开始使用Node.js驱动程序

Install dependencies安装依赖项

Ensure you have the following dependencies installed in your development environment:确保在开发环境中安装了以下依赖项：

• Node.js v16.20.1 or laterNode.js v16.20.1或更高版本

• npm (Node Package Manager)（Node包管理器）

To learn how to install Node.js and npm, see Downloading and installing Node.js and npm in the npm documentation.要了解如何安装Node.js和npm，请参阅npm文档中的下载和安装Node.js与npm。

Create a project directory创建项目目录

In your shell, run the following command to create a directory called node_quickstart for this project:在shell中，运行以下命令为此项目创建一个名为node_quickstart的目录：

mkdir node_quickstart

Then, run the following commands to navigate into the directory and initialize your Node.js project:然后，运行以下命令导航到目录并初始化Node.js项目：

cd node_quickstart
npm init -y

When the initialization command successfully completes, you have a package.json file in your node_quickstart directory.当初始化命令成功完成时，您的node_quickstart目录中有一个package.json文件。

Install the Node.js Driver安装Node.js驱动程序

Run the following command from your project directory to install the driver:从项目目录运行以下命令以安装驱动程序：

npm install mongodb@7.0

This command performs the following actions:此命令执行以下操作：

• Downloads the mongodb package and the dependencies it requires下载mongodb包及其所需的依赖项

• Saves the package in the node_modules directory将包保存在node_modules目录中

• Records the dependency information in the package.json file在package.json文件中记录依赖关系信息

Create a free MongoDB deployment on Atlas在Atlas上创建免费的MongoDB部署

Complete the MongoDB Get Started guide to set up a new Atlas account and load sample data into a new free tier MongoDB deployment.完成MongoDB开始使用指南，以设置新的Atlas帐户并将示例数据加载到新的免费层MongoDB部署中。

Save your credentials保存您的凭据

After you create your database user, save that user's username and password to a safe location for use in an upcoming step.创建数据库用户后，将该用户的用户名和密码保存到安全位置，以便在接下来的步骤中使用。

Find your MongoDB Atlas connection string查找您的MongoDB Atlas连接字符串

To retrieve your connection string for the deployment that you created in the previous section, log into your Atlas account and navigate to the Clusters section and click the Connect button for your new deployment.要检索您在上一节中创建的部署的连接字符串，请登录您的Atlas帐户并导航到“聚集”部分，然后单击新部署的“连接”按钮。

Copy your connection string复制您的连接字符串

Click the button on the right of the connection string to copy it to your clipboard, as shown in the following screenshot:单击连接字符串右侧的按钮将其复制到剪贴板，如下图所示：

Update the placeholders更新占位符

Paste your connection string into a file in your preferred text editor and replace the username and <db_password> placeholders with your database user's username and password.将连接字符串粘贴到首选文本编辑器中的文件中，并将username和<db_password>占位符替换为数据库用户的用户名和密码。

Save this file to a safe location for use in the next section.将此文件保存到安全位置，以便在下一节中使用。

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

In your node_quickstart directory, create a file called index.js for your application.在node_quickstart目录中，为您的应用程序创建一个名为index.js的文件。

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');

async function runGetStarted() {
  // 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);

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

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

    console.log(movie);
  } finally {
    await client.close();
  }
}
runGetStarted().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>占位符替换为您从本指南的“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

From your project directory, run the following command to start the application:在项目目录中，运行以下命令以启动应用程序：

node index.js

The output includes details about the retrieved movie document:输出包括有关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, verify that 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看到输出，请验证是否在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。