javascript - 如何使用参数设置 Express 路线

Question

我正在构建一个 MEVN 堆栈 CRUD 应用程序(Vue、Node、Express、MongoDB)。我正在尝试为我的应用程序设置以下 Express 路线...

postRoutes.get('/view/:id', async (req, res) => {
  const collection = await loadPostsCollection();
  let id = req.params.id;
  res.send(await collection.find({}).toArray());
  res.status(201).send();
});

...以便它根据数据的 id 从 MongoDB 返回特定数据。我不确定如何设置 res.send 以便它根据 req.params.id 查找数据。我尝试像这样传递 req.params.id ...

postRoutes.get('/edit/:id', async (req, res) => {
  const collection = await loadPostsCollection();
  let id = req.params.id;
  res.send(await collection.find({ _id: mongodb.ObjectId(req.params.id)}).toArray());
  res.status(201).send();
});

...但这也不起作用。知道如何设置此路由以便它根据 ID 参数查找数据吗？谢谢!

我的完整 Express 路由器页面如下:

const express = require('express');
const postRoutes = express.Router();
const mongodb = require('mongodb')


postRoutes.get('/', async (req, res) => {
  const collection = await loadPostsCollection();
  res.send(await collection.find({}).toArray());
});


postRoutes.post('/add', async (req, res) => {
  const collection = await loadPostsCollection();
  let task = req.body;
  await collection.insertOne(task);
  res.status(201).send();
});

postRoutes.get('/view/:id', async (req, res) => {
  const collection = await loadPostsCollection();
  let id = req.params.id;
  res.send(await collection.find({}).toArray());
  res.status(201).send();
});

postRoutes.delete('/delete/:id', async (req, res, next) => {
  const collection = await loadPostsCollection();
  collection.deleteOne({ _id: mongodb.ObjectId(req.params.id) });
  res.status(200).send({});
});

async function loadPostsCollection() {
  const client = await mongodb.MongoClient.connect(
    '...',
    {
      useNewUrlParser: true
    }
  );
  return client.db("test").collection("todos")
}

module.exports = postRoutes;

Answer 1

你最好使用 findOne 方法，如下所示:

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

postRoutes.get("/view/:id", async (req, res) => {
  const collection = await loadPostsCollection();
  let id = req.params.id;

  let result = await collection.findOne({
    _id: new ObjectID(id)
  });

  if (!result) {
    return res.status(400).send("Not found");
  }

  res.status(200).send(result);
});