没有mongoose 的 Express 和 MongoDB

根据我的经验，我们总是定义一个单独的实用程序，在应用程序启动时加载连接池，然后重用这些连接.

在上述方法中，您似乎在 for each HTTP请求创建一个新连接，然后不终止(或)关闭连接.对于大型应用程序来说，这可能很昂贵.

db.util.js

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

const uri = `mongodb://${process.env.DB_USER}:${process.env.DB_PASSWORD}@localhost:27017/${process.env.DATABASE}?maxPoolSize=2-&w=majority`;

const client = new MongoClient(uri);

const init = async () => {
  try {
    await client.connect();
    console.log("Connected");
  } catch (error) {
    console.log(error);
  }
};

const getClient = () => {
  return client;
};

module.exports.init = init;
module.exports.getClient = getClient;

app.js

//Import modules
require("dotenv").config({ path: __dirname + "/.env" });
const express = require("express");
const dogRoutes = require("./routes/dog.routes");
const db = require("./utils/db.util");

// Define PORT for HTTP Server
const PORT = 9900;

// Initialize Express
const app = express();

app.use(express.json());
app.use(dogRoutes);

(async () => {
  await db.init();

  app.listen(PORT, (err) => {
    console.log(`Server is up at localhost ${PORT}`);
  });
})();