javascript - Mongoose、express 返回空数组

Question

我读过很多类似的问题，讨论 Mongoose 默认模型名称的复数化。尽管这似乎不适用于本案。问题是它返回一个空数组。我的本地 mongoDB 在“userData”集合中包含 2 个文档，它们如下所示:

{
        "_id" : ObjectId("5dcd0582587ac600ec9323a5"),
        "name" : "John",
        "surname" : "Doe",
        "team" : "CE",
        "project" : "Project1",
        "id" : "2"
}

然后这是我的模型User.js:

const mongoose = require('mongoose');
const { Schema } = mongoose;

const userSchema = new Schema({
    name: 'String',
    surname: 'String',
    team: 'String',
    project: 'String',
    id: 'String'
}, { collection: 'UserData' });

module.exports = mongoose.model('user', userSchema);

这是我的路线userRoutes.js:

const mongoose = require('mongoose');
const User = mongoose.model('user');

module.exports = (app) => {

  app.get(`/`, async (req, res) => {
    let users = await User.find();
    return res.status(200).send(users);
  });

  app.post(`/user`, async (req, res) => {
    let user = await User.create(req.body);
    return res.status(201).send({
      error: false,
      user
    })
  })

  app.put(`/user/:id`, async (req, res) => {
    const { id } = req.params;
    let user = await User.findByIdAndUpdate(id, req.body);
    return res.status(202).send({
      error: false,
      user
    })

  });

  app.delete(`/user/:id`, async (req, res) => {
    const { id } = req.params;
    let user = await User.findByIdAndDelete(id);
    return res.status(202).send({
      error: false,
      user
    })

  })

}

最后这是我的起点index.js:

const express = require('express');
const mongoose = require('mongoose'); /*-- Import the mongoose module --*/
const bodyParser = require('body-parser');
require('./models/User');

const app = express();

mongoose.Promise = global.Promise;
mongoose.connect('mongodb://localhost:27017/users', { useUnifiedTopology: true, useNewUrlParser: true })  
  .then(() => console.log('Database Connection Succesful'))
  .catch(err => console.log('Database Connection Error0'));

var db = mongoose.connection;

db.on('error', console.error.bind(console, 'MongoDB connection error:'));
app.use(bodyParser.json());

require('./routes/userRoutes')(app);

if (process.env.NODE_ENV === 'production') {
  app.use(express.static('client/build'));

  const path = require('path');
  app.get('*', (req, res) => {
    res.sendFile(path.resolve(__dirname, 'client', 'build', 'index.html'))
  })

}

const PORT = process.env.PORT || 5000;
app.listen(PORT, () => {
  console.log(`app running on port ${PORT}`)
});

那么我的返回是一个空数组[]。任何帮助表示赞赏。

Answer 1

在架构代码中，您需要定义字段类型，例如 name: String 而不是 name: "String"。

您的架构必须如下所示:

const mongoose = require("mongoose");
const { Schema } = mongoose;

const userSchema = new Schema(
  {
    name: String,
    surname: String,
    team: String,
    project: String,
    id: String
  },
  { collection: "UserData" }
);

module.exports = mongoose.model("user", userSchema);

此外，您已经创建了用户模型，因此在 userRoute 中不需要这样做:

const User = mongoose.model('user');

您只需要在 userRoute 中正确导入这样的 User 模型即可。

const User = require("../models/User"); // you can change the path if it is not correct

最后，要启用发布数据的 json，您需要将此行添加到您的 index.js 中:

app.use(bodyParser.json()); 

通过这些更改，您可以使用此 url http://localhost:3000/user 创建用户使用像这样的 json 主体:

{
    "name": "John",
    "surname": "Doe",
    "team": "CE",
    "project": "Project1",
    "id": "2"
}

这将给出如下结果:

{
    "error": false,
    "user": {
        "_id": "5dce7f8c07d72d4af89dec57",
        "name": "John",
        "surname": "Doe",
        "team": "CE",
        "project": "Project1",
        "id": "2",
        "__v": 0
    }
}

此时您将拥有一个 UserData 集合。

当您向 http://localhost:5000 发送 get 请求时url，你会得到这样的用户:

[
    {
        "_id": "5dce75a91cbb4e5f7c5ebfb3",
        "name": "John",
        "surname": "Doe",
        "team": "CE",
        "project": "Project1",
        "id": "2",
        "__v": 0
    }
]