在电子邮件索引Mongodb中使用唯一，无法提醒'user already registered'

Question

unique:true确实停止添加到数据库，但只得到catch(e(错误消息。尝试使用findOne方法，但作为一个初学者，架构一直让我感到困惑。

require('dotenv').config()
const express = require('express')
const cors = require('cors')
const bodyParser = require('body-parser')
const mongoose = require('mongoose')
const app = express();
const urlencodedParser = bodyParser.urlencoded({ extended: false })
app.use(bodyParser.json(), urlencodedParser);
app.use(cors());
const dbURI = 
`mongodb+srv://${process.env.REACT_APP_DB_USERNAME}:${process.env.REACT_APP_DB_PASSWORD}@cluster0.sd1id.mongodb.net/register?retryWrites=true&w=majority`
mongoose.connect(dbURI, { useNewUrlParser:true, useUnifiedTopology:true })
.then((res) => {
const User = mongoose.model('users', UsersSchema);
User.createIndexes();

我认为这里有问题。直接进入错误，而不是else循环。

app.post('/register', async (req, res) => {
try {
const user = new User(req.body);
let result = await user.save();
result = result.toObject();
// console.log(result);
if (result) {
delete result.password;
res.send(req.body);
// console.log(result);
} else {
console.log("User already registered!");
}
} catch (e) {
console.log("Something went wrong!");
}
})
})
.catch(err => console.log(err))
const UsersSchema = new mongoose.Schema({
email: {
type: String,
unique: true,
required: true,
},
password: {
type: String,
required: true,
}
})

app.listen(3001, () => console.log("Server is listening to port 3001"))

Answer 1

您的代码中有一些混乱。。。

app.js

require('dotenv').config()
const express = require('express')
const cors = require('cors')
const bodyParser = require('body-parser')
const mongoose = require('mongoose')
const app = express();
const createUser = require('registerController');
// repleace 3000 with a port number of your choice
const port = 3000 || process.env.PORT;
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(cors());
app.post('/register', createUser);
const dbURI = 
`mongodb+srv://${process.env.REACT_APP_DB_USERNAME}:${process.env.REACT_APP_DB_PASSWORD}@cluster0.sd1id.mongodb.net/register?retryWrites=true&w=majority`
mongoose.connect(dbURI, { useNewUrlParser:true, useUnifiedTopology:true })
.then(() => {
app.listen(port, () => console.log(`Server listening on Port ${port}`));
});

User.js

const mongoose = require('mongoose');
const userSchema = new mongoose.Schema({
email: {
type: String,
unique: true,
required: true,
},
password: {
type: String,
required: true,
}
});
module.exports = mongoose.model('User', userSchema);

registerController.js

const User = require('User');
const createUser = async (req, res) => {
try {
const user = await User.create(req.body);
// console.log(user);
if (user) {
delete user.password;
res.send(req.body);
// console.log(user);
} else {
console.log("User already registered!");
}
} catch (e) {
console.log("Something went wrong!");
}
};
module.exports = createUser;