Can I run my middleware and query MYSQL in Nuxt universal mode (not spa)? How exactly?

Question

Vue.js

Hello.
If I installed Nuxt as Universal, does that mean I can use the backend or not? And if I can - then how, for example, to make a query to the database?
I also tried to install with Express (I chose the option when installing Nuxt), but when I try to embed middleware in server/index.js - there are some incomprehensible errors - I didn’t find simple examples ...
Please explain exactly how I can use the server part in Nuxt. js to work with a database (mysql)?
At first I thought to make a separate Express on a different port, but now I decided that it would be a crutch - maybe it's possible somehow differently? Like Nuxt way))
Thank you.

Answer 1

I only study JS and NUXT, but as part of self-study, I did this.
I ask more experienced to point out the errors:

// nuxt.config.js
...
  serverMiddleware: [
    '~api/api'
  ],
...

//api.js

import {pool} from "./db";

const express = require('express');
const app = express();

app.get('/valute', function (req, res) {
  const sql = "SELECT * FROM `valute-xml`";

  pool.query(sql, function (error, results, fields) {
    if (error) throw error;
    res.json(results);
  });
});

//db.js

const mysql = require('mysql2');

const pool = mysql.createPool({
  connectionLimit: 100,
  host: '',
  user: '',
  password: '',
  database: ''
});

export {pool}

Then, with the help of axios, I turn, for example, to localhost: 3000/api/valute

Answer 2

Nuxt is a front-end and server-side rendering. (server rendering != backend)
It does not perform backend tasks and is not made for this.
this is how it works, api on a separate domain / port, nuxt itself and accesses the api. API can be done with anything, not just JS.