Delete Documents删除文档

deleteOne() Example: Full FiledeleteOne()示例：完整文件

The following code is a complete, standalone file that performs a delete one operation:以下代码是一个完整的独立文件，用于执行删除操作：

// Delete a document删除文档

import { MongoClient } from "mongodb";

// Replace the uri string with your MongoDB deployment's connection string将uri字符串替换为MongoDB部署的连接字符串
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");

    /* Delete the first document in the "movies" collection that matches the specified query document删除“电影”集合中与指定查询文档匹配的第一个文档 */
    const query = { title: "Annie Hall" };
    const result = await movies.deleteOne(query);

    /* Print a message that indicates whether the operation deleted a document打印一条消息，指示操作是否删除了文档 */
    if (result.deletedCount === 1) {
      console.log("Successfully deleted one document.");
    } else {
      console.log("No documents matched the query. Deleted 0 documents.");
    }
  } finally {
    // Close the connection after the operation completes操作完成后关闭连接
    await client.close();
  }
}
// Run the program and print any thrown exceptions运行程序并打印任何抛出的异常
run().catch(console.dir);

Running the preceding example results in the following output:运行前面的示例会得到以下输出：

Successfully deleted one document.

If you run the example more than once, the code produces the following output because you deleted the matching document in the first run:如果您多次运行该示例，代码将产生以下输出，因为您在第一次运行中删除了匹配的文档：

No documents matched the query. Deleted 0 documents.

deleteMany() Example: Full FiledeleteMany()示例：完整文件

The following code is a complete, standalone file that performs a delete many operation:以下代码是一个完整的独立文件，用于执行删除多个操作：

// Delete multiple documents删除多个文档

import { MongoClient } from "mongodb";

// Replace the uri string with your MongoDB deployment's connection string.将uri字符串替换为MongoDB部署的连接字符串。
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");

    /* Delete all documents that match the specified regular expression in the title field from the "movies" collection从“电影”集合中删除与标题字段中指定的正则表达式匹配的所有文档 */
    const query = { title: { $regex: "Santa" } };
    const result = await movies.deleteMany(query);

    // Print the number of deleted documents打印已删除文档的数量
    console.log("Deleted " + result.deletedCount + " documents");
  } finally {
    // Close the connection after the operation completes操作完成后关闭连接
    await client.close();
  }
}
// Run the program and print any thrown exceptions运行程序并打印任何抛出的异常
run().catch(console.dir);

// Delete multiple documents删除多个文档

import { MongoClient } from "mongodb";

// Replace the uri string with your MongoDB deployment's connection string将uri字符串替换为MongoDB部署的连接字符串
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");

    /* Delete all documents that match the specified regular expression in the title field from the "movies" collection从“电影”集合中删除与标题字段中指定的正则表达式匹配的所有文档 */
    const result = await movies.deleteMany({ title: { $regex: "Santa" } });
    
    // Print the number of deleted documents打印已删除文档的数量
    console.log("Deleted " + result.deletedCount + " documents");
  } finally {
    // Close the connection after the operation completes操作完成后关闭连接
    await client.close();
  }
}
// Run the program and print any thrown exceptions运行程序并打印任何抛出的异常
run().catch(console.dir);

Running the preceding example for the first time results in the following output:第一次运行前面的示例会得到以下输出：

Deleted 19 documents

If you run the example more than once, you see the following output because you deleted the matching documents in the first run:如果您多次运行该示例，则会看到以下输出，因为您在第一次运行中删除了匹配的文档：

Deleted 0 documents