尝试将 mongoose 连接到我的 mongodb 并出现浏览器内错误

Question

The code compiles fine in my editor, but only shows up in my browser app:

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

mongoose.connect(process.env.DATABASE_URL, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', () => {
  console.log('Connected to the database');
});

const Index = () => {
    const [postText, setPostText] = useState('');

    const handleSubmit = (e) => {
        e.preventDefault();
        // add code here to handle form submission and create a post
        setPostText('');
    }

    return (
        <div>
            <h1>Welcome to My Social Media App</h1>
            <form onSubmit={handleSubmit}>
                <textarea value={postText} onChange={(e) => setPostText(e.target.value)} placeholder="What's on your mind?"/>
                <button type="submit">Post</button>
            </form>
        </div>
    )
}

export default Index;

Unhandled Runtime Error TypeError: mongoose__WEBPACK_IMPORTED_MODULE_2___default(...).connect is not a function

I was just trying to get it to connect to my mongodb and honestly I tried a few things that were suggested to me by chatgpt because I am learning to code using it so I just asked it to fix it but it couldn't. I'm not sure what else I should say.

I got this error at first:

TypeError: mongoose.connect is not a function

so I tried:

This error is usually caused when you forget to import the mongoose module in your file. Please make sure you have the following line at the top of your file:

javascript Copy code

const mongoose = require("mongoose");

Additionally, make sure that you have installed the mongoose package in your project by running npm install mongoose.

and this:

The error is occurring because you are trying to call the connect function on the mongoose module, but mongoose has not been imported correctly.

Try changing this line:

javascript Copy code

const mongoose = require('mongoose');

to this:

python Copy code

import mongoose from 'mongoose';

This should resolve the error and allow you to connect to the MongoDB database using Mongoose.

then this:

The issue is that the mongoose module is being imported using the require statement which is commonly used for CommonJS modules. However, since you are using a Next.js application which is built using ES6 modules, you need to use the import statement instead:

javascript Copy code

import mongoose from 'mongoose';

mongoose.connect(process.env.DATABASE_URL, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', () => {
  console.log('Connected to the database');
});

Answer 1

So, following Matt's comment, I fed his response to chatGPT and this is the code it spit out, which fixes the issue:

Here's how you can use getServerSideProps to fix the error in your code:

javascript Copy code

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

const Index = () => {
    const [postText, setPostText] = useState('');

    const handleSubmit = (e) => {
        e.preventDefault();
        // add code here to handle form submission and create a post
        setPostText('');
    }

    return (
        <div>
            <h1>Welcome to My Social Media App</h1>
            <form onSubmit={handleSubmit}>
                <textarea value={postText} onChange={(e) => setPostText(e.target.value)} placeholder="What's on your mind?"/>
                <button type="submit">Post</button>
            </form>
        </div>
    )
}

export async function getServerSideProps(context) {
    await mongoose.connect(process.env.DATABASE_URL, {
        useNewUrlParser: true,
        useUnifiedTopology: true,
    });

    const db = mongoose.connection;
    db.on('error', console.error.bind(console, 'connection error:'));
    db.once('open', () => {
        console.log('Connected to the database');
    });

    return {
        props: {},
    };
}

export default Index;

This way, the mongoose code will only run on the server-side and will not interfere with the client-side rendering.