• 对不起，如果我没有提供正确的代码 *
  我正在安装mongoDB并尝试连接，但出现此错误

errno: -4078, code: 'ECONNREFUSED', syscall: 'connect', address: '::1', port: 27017 }, [Symbol(errorLabels)]: Set(1) { 'ResetPool' }}, topologyVersion: null, setName: null, setVersion: null, electionId: null, logicalSessionTimeoutMinutes: null, primary: null, me: null, '$clusterTime': null }

我不知道该怎么做因为这是我的第一次
我在这里创建了两个文件夹，名为frontend和backend。

前端代码

`import React, { useState } from 'react';

function App() {
const \[formData, setFormData\] = useState({
name: '',
email: '',
message: ''
});

const handleInputChange = (event) =\> {
const { name, value } = event.target;
setFormData({ ...formData, \[name\]: value });
};

const handleSubmit = async (event) =\> {
event.preventDefault();

    try {
      const response = await fetch('/submit-form', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(formData)
      });
    
      if (response.ok) {
        alert('Form submitted successfully!');
        setFormData({
          name: '',
          email: '',
          message: ''
        });
      } else {
        throw new Error('Form submission failed.');
      }
    } catch (error) {
      console.error('Error:', error);
      alert('Form submission failed.');
    }

};

return (
\<div\>

<h1>Form</h1>
\
\
Name:
\<input
            type="text"
            name="name"
            value={formData.name}
            onChange={handleInputChange}
          /\>
\
<br />
\
Email:
\<input
            type="email"
            name="email"
            value={formData.email}
            onChange={handleInputChange}
          /\>
\
<br />
\
Message:
\<textarea
            name="message"
            value={formData.message}
            onChange={handleInputChange}
          \>\
\
<br />
\Submit\
\
\
);
}

export default App;

后端代码

const express = require('express'); const { MongoClient } = require('mongodb');

const app = express(); const port = 5000;

app.use(express.urlencoded({ extended: true })); app.use(express.json());

const mongoURL = 'mongodb://localhost:27017'; const dbName = 'formDB';

MongoClient.connect(mongoURL, (err, client) => { if (err) { console.error('Failed to connect to the database:', err); return; }

console.log('Connected to MongoDB!'); const db = client.db(dbName);

// Define routes and form handling logic here

// Handle form submission app.post('/submit-form', (req, res) => { const formData = req.body;

// Save form data to MongoDB
const collection = db.collection('forms');
collection.insertOne(formData, (err, result) => {
  if (err) {
    console.error('Failed to save form data:', err);
    res.status(500).send('Internal Server Error');
    return;
  }

  console.log('Form data saved:', result);
  res.status(200).send('Form submitted successfully!');
});

});

app.listen(port, () => { 
    console.log(Server is running on http://localhost:${port}); 
})

所以，我这里的问题是，我无法使用上面的后端代码连接mongoDB，它抛出错误。我非常感谢你的帮助。