参考：

初始化示例项目

mkdir node-mongodb-demo

cd node-mongodb-demo

npm init -y

npm install mongodb

连接到 MongoDB

const { MongoClient } = require(“mongodb”); // Connection URI const uri = “mongo://127.0.0.1:27017”; // Create a new MongoClient const client = new MongoClient(uri); async function run() { try { // Connect the client to the server await client.connect(); // Establish and verify connection await client.db(“admin”).command({ ping: 1 }); console.log(“Connected successfully to server”); } catch () { console.log(‘Connect failed’) } finally { // Ensures that the client will close when you finish/error await client.close(); } } run()

在Node中操作MongoDB-连接MongoDB - 图1

CRUD 操作

CRUD（创建，读取，更新，删除）操作使您可以处理存储在 MongoDB 中的数据。

创建文档

插入一个：

const pizzaDocument = { name: “Neapolitan pizza”, shape: “round”, toppings: [ “San Marzano tomatoes”, “mozzarella di bufala cheese” ], }; const result = await pizzaCollection.insertOne(pizzaDocument); console.dir(result.insertedCount);

插入多个：

const pizzaDocuments = [ { name: “Sicilian pizza”, shape: “square” }, { name: “New York pizza”, shape: “round” }, { name: “Grandma pizza”, shape: “square” }, ]; const result = pizzaCollection.insertMany(pizzaDocuments); console.dir(result.insertedCount);

查询文档

const findResult = await orders.find({ name: “Lemony Snicket”, date: { $gte: new Date(new Date().setHours(00, 00, 00)), $lt: new Date(new Date().setHours(23, 59, 59)), }, });

删除文档

const doc = { pageViews: { $gt: 10, $lt: 32768 } }; // 删除符合条件的单个文档 const deleteResult = await collection.deleteOne(doc); console.dir(deleteResult.deletedCount); // 删除符合条件的多个文档 const deleteManyResult = await collection.deleteMany(doc); console.dir(deleteManyResult.deletedCount);

修改文档

更新1个文档：

const filter = { _id: 465 }; // update the value of the ‘z’ field to 42 const updateDocument = { $set: { z: 42, }, }; // 更新多个 const result = await collection.updateOne(filter, updateDocument); // 更新多个 const result = await collection.updateMany(filter, updateDocument);

替换文档：

const filter = { _id: 465 }; // replace the matched document with the replacement document const replacementDocument = { z: 42, }; const result = await collection.replaceOne(filter, replacementDocument);