"Cannot overwrite model once compiled" Next.js and Mongoose Schemas - node.js

Question

First time using Next.js, I'm trying to implement a Node.js server with MongoDB database, schema models and routes.
I'm not sure what I'm doing wrong, since I tried a lot of combinations, as you can see in the comments in my code. I need to use the models but I'm getting the following error:
"OverwriteModelError: Cannot overwrite termscon model once compiled."
server/models/TermsCon.js:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
// Create Schema
const TermsConSchema = new Schema({
_id: {
type: String,
required: true,
default: "1"
},
text: {
type: String,
required: true,
default: "Lorem Ipsum"
}
});
// const TermsCon = mongoose.model.termscon || mongoose.model('termscon', TermsConSchema);
// module.exports = TermsCon;
// module.exports = mongoose.model('termscon', TermsConSchema);
// export default mongoose.model.TermsCon || mongoose.model('termscon', TermsConSchema)
module.exports = TermsCon = mongoose.model('termscon', TermsConSchema);
server/routes/api/termscons.js:
const express = require('express')
const mongoose = require('mongoose');
const router = express.Router()
const TermsCon = require('../../models/TermsCon')
// const TermsCon = mongoose.model('termscon')
router.get('/', (req, res) => {
TermsCon.find()
.then(tc => {
res.json(tc)
})
});
module.exports = router;
server/index.js:
const express = require('express')
const next = require('next')
const mongoose = require('mongoose')
const port = process.env.PORT || 3000
const dev = process.env.NODE_ENV !== 'production'
const app = next({ dev })
const handle = app.getRequestHandler()
app.prepare().then(() => {
mongoose
.connect(process.env.MONGODB_URI,
{
useNewUrlParser: true,
useUnifiedTopology: true,
useNewUrlParser: true,
useUnifiedTopology: true,
useCreateIndex: true
}
)
.then(() => console.log('MongoDB Connected...'))
.catch(err => console.log(err));
const server = express()
server.use("/api/termscons", require("./routes/api/termscons"))
server.get('*', (req, res) => {
return handle(req, res)
})
server.listen(port, (err) => {
if (err) throw err
console.log(`Server started on port ${port}`)
})
})
pages/index.js:
import axios from 'axios'
import { useState, useEffect } from 'react'
export default function Home() {
const [ tc, setTc ] = useState()
useEffect(() => {
axios.get('/api/termscons')
.then(res => {
setTc(res.data)
})
.catch(err =>console.log("ERR: ", err))
}, [])
return (
<div>
{tc ?
<p>{tc}</p>
: null}
</div>
)
}
Is it something wrong with the way I'm exporting my schema? With the way I'm connecting to my MongoDB? The routes? Pages?
Any idea will be much appreciated! Thanks!

Answer 1

So I changed the structure:
I gave up creating a custom server since it didn't helped me at all in my Next.js app.
So I don't have any server/index.js anymore or server/routes/api. Actually, there is no "server" folder at all. I simply created a mongodb connection separatelly to help me connect to my database, wich I call at each server api call, like so:
utils/dbConnect.js:
import mongoose from 'mongoose'
async function dbConnect() {
await mongoose.connect(process.env.MONGODB_URI, {
useNewUrlParser: true,
useUnifiedTopology: true,
useFindAndModify: false,
})
}
export default dbConnect
Since I don't have a custom server anymore, I don't have server/routes/api either. So for the api routes I use the default next.js api folder:
pages/api/termscons.js:
import dbConnect from '../../../utils/dbConnect'
import TermsCon from '../../../models/TermsCon'
export default async function handler(req, res) {
await dbConnect()
switch (req.method) {
case 'GET':
try {
const tc = await TermsCon.find()
res.status(200).json(tc)
} catch (error) {
res.status(400).json({ itemnotfound: "No item found" })
}
break
default:
res.status(400).json({ itemnotfound: "No item found" })
break
}
}
To conclude, I have a folder with all my models in my app main folder:
models/TermsCon.js:
import mongoose from 'mongoose'
const TermsConSchema = new mongoose.Schema({
_id: {
type: String,
required: true,
default: "1"
},
text: {
type: String,
required: true,
default: "Lorem Ipsum"
}
});
export default mongoose.models.TermsCon || mongoose.model('termscon', TermsConSchema);