连接 MongoDB 到 Koa 服务器问题

Question

我已经在我的 Koa 服务器上沉寂了一段时间了。看起来我已经很接近了，但我似乎无法完全完成它。

每当我想向消息数据库发布某些内容时，它就会崩溃并显示拓扑已关闭。

我目前正在通过邮递员添加非常基本的 json 文件，其中包含 msg 和 id 属性，希望更有经验的人可以帮助我解决这个问题。肯定会非常感激。

const Koa = require("koa");
const bodyparser = require("koa-bodyparser");
const KoaRouter = require("koa-router");
const { MongoClient } = require('mongodb');
const url = 'mongodb://localhost:27017/';

const app = new Koa();
const router = new KoaRouter();
const client = new MongoClient(url);
const db = client.db('serverTesting');
const messages = db.collection("messsages")

const PORT = 3002;

app.use(bodyparser())

// router

app.use(router.routes());

router.get("/", ctx => {
    ctx.body = "Hello, this is the Homepage.";
});

router.get("/test", ctx => {
    ctx.body = { msg: "Hello Test"};
});

router.post("/test", ctx => {
    const message = ctx.request.body;
    messages.insertOne(message);
    ctx.body = "Message was updated."
    console.log("Added message to database: ")
    console.log(messages);
});

router.delete("/test", ctx => {
    const msg = ctx.request.body.msg;
    const deleted = messages.find(message => message.msg === msg);
    if (deleted) {
        messages = messages.filter(message => message.msg !== msg);
        console.log("Deleted message from database: ")
        console.log(messages)
        ctx.body = "Message was deleted."

    } else {
        ctx.body = "This message was not found in the database"
    }
})

router.put("/test", ctx => {
    const id = ctx.request.body.id;
    const deleted = messages.find(message => message.id === id);
    if (deleted) {
        messages.forEach(message => {
            if (message.id === id) {
                message.msg = ctx.request.body.msg
            }
        })
        console.log("Updated message in database: ")
        console.log(messages)
        ctx.body = "Message was updated."
    } else {
        ctx.body = "This message was not found in the database"
    }
})

app.listen(PORT, () => {
    client.connect()
    console.log(`Server running on http://localhost:${PORT} 
              

Answer 1

我不完全知道您的代码问题是什么，因为它对我有用，也许与您的数据库设置有关。

我建议一个有效的例子，您可以自己尝试。

我假设您有 docker 和 curl 在您的系统中。

docker-compose.yaml

version: '3.1'
services:
  mongo:
    image: mongo
    restart: always
    ports:
      - "27077:27017"
    environment:
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: example
  mongo-express:
    image: mongo-express
    restart: always
    ports:
      - "8077:8081"
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: root
      ME_CONFIG_MONGODB_ADMINPASSWORD: example
      ME_CONFIG_MONGODB_URL: mongodb://root:example@mongo:27017/

create docker-compose.yaml and 和运行Docker组成。这将使Mongo Express在8077端口上运行，并且DB本身在27077上。

index.js

const Koa = require("koa");

const bodyparser = require("koa-bodyparser");

const KoaRouter = require("koa-router");

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

(async () => {

  const PORT = 3002;

  const url = "mongodb://root:[email protected]:27077/";
  const client = await new MongoClient(url).connect();

  const db = client.db("my-database");

  const messages = db.collection("messages");
  const app = new Koa();

  const router = new KoaRouter();
  app.use(bodyparser());

  app.use(router.routes());
  router.post("/create", async (ctx) => {

    const message = ctx.request.body;

    await messages.insertOne(message);

    ctx.body = "DB record created";

  });
  app.listen(PORT, "0.0.0.0", () => {

    console.log(`Server running on http://127.0.0.1:${PORT}