如何使用MongoDB开发一个在线聊天系统（mongodb入门

const { MongoClient } = require(mongodb); 内容来自zvvq

const url = "mongodb://localhost:27017";

内容来自zvvq，别采集哟

const dbName = "chat_system";

(async function connectMongoDB() { zvvq.cn

try { 内容来自zvvq

const client = await MongoClient.connect(url);

内容来自samhan

const db = client.db(dbName);

console.log(Connected successfully to MongoDB);

内容来自samhan

// 后续操作放在这里

client.close();

内容来自samhan

} catch (err) { zvvq.cn

console.log(err);

} zvvq好，好zvvq

})();

const { MongoClient } = require(mongodb);

const url = "mongodb://localhost:27017";

zvvq好，好zvvq

const dbName = "chat_system";

(async function createUser(username, password, avatar) { 本文来自zvvq

try {

copyright zvvq

const client = await MongoClient.connect(url); 本文来自zvvq

const db = client.db(dbName);

内容来自samhan

const user = {

username,

password, 内容来自zvvq，别采集哟

avatar zvvq

}; 内容来自samhan

const result = await db.collection(users).insertOne(user); 本文来自zvvq

console.log(`User ${username} has been created`);

client.close(); 内容来自zvvq，别采集哟

} catch (err) {

内容来自samhan

console.log(err);

内容来自samhan666

}

zvvq.cn

})(test, 123456, avatar.png); copyright zvvq

const { MongoClient } = require(mongodb);

zvvq好，好zvvq

const url = "mongodb://localhost:27017";

zvvq好，好zvvq

const dbName = "chat_system"; 内容来自samhan

(async function sendMessage(senderId, receiverId, content) {

copyright zvvq

try {

const client = await MongoClient.connect(url);

const db = client.db(dbName);

const message = { 内容来自samhan666

senderId, zvvq.cn

receiverId, 内容来自zvvq

content, zvvq好，好zvvq

createdAt: new Date()

内容来自samhan666

}; 内容来自zvvq

const result = await db.collection(messages).insertOne(message);

zvvq.cn

console.log(Message has been sent);

client.close(); 内容来自samhan666

} catch (err) {

console.log(err);

} 内容来自zvvq

})(user1, user2, Hello); copyright zvvq