How to get data from the module that pulls the database, nodejs / express?

Question

MySQL

Good afternoon! I beg you to explain!
What to use in this case, so that it is not shitty code and everything works?
Wrote a module that retrieves data from the database. How to get data from the database is clear!
it is not clear how to transfer them further to another module, how can I get a response from this module?
Please explain at least how this is done, in which direction to look?
Ideally, this would be some kind of example.
Thank you!
The module itself

function getDataFromDatabase() {
  var arr = []
  var con = mysql.createConnection(conf.config);
  return con.connect(function (err) {

    if(err) throw err;
    con.query("SELECT DID, DName FROM Device")
    .on('result', function (data) {

      arr.push(data)
    })
    .on('end', function () {
      return JSON.stringify(arr)

    })
  });
}

getDataFromDatabase()
module.exports.getDataFromDatabase = getDataFromDatabase;

Answer 1

Can be done with callback

var getDataFromDatabase = function () {
  var arr = []
  var con = mysql.createConnection(conf.config);
  con.connect(function (err) {

    if(err) throw err;
    con.query("SELECT DID, DName FROM Device")
    .on('result', function (data) {
      arr.push(data)
    })
    .on('end', function () {
      return callback(null, arr);
    })
    .on('error', function(err){
        return callback (err, null);
    });
}

module.exports = {
    getDataFromDatabase
}

Then you call

var fromDB = require(./modulName);
fromDB.getDataFromDatabase(function(err, result){
    if(err){
        console.log(err);
    } else {
        console.log(result);
    }
})

Can be done through a promise

var getDataFromDatabase = function (callback) {
    return new Promise((resolve, reject) => {
        var arr = []
        var con = mysql.createConnection(conf.config);
        con.connect(function (err) {

            if (err) throw err;
            con.query("SELECT DID, DName FROM Device")
                .on('result', function (data) {
                    arr.push(data)
                })
                .on('end', function () {
                    return resolve(arr);
                })
                .on('error', function (err) {
                    return reject(err);
                })
        });
    })
}

module.exports = {
    getDataFromDatabase
}

Call

var fromDB = require("./modulName");
fromDB.getDataFromDatabase()
    .then(result =>{
        console.log(result);
    },(err)=>{
        console.log(err);
    })

Well, through asynchronous functions too

var getDataFromDatabase = async function (callback) {
    return new Promise((resolve, reject) => {
        var arr = []
        var con = mysql.createConnection(conf.config);
        con.connect(function (err) {

            if (err) throw err;
            con.query("SELECT DID, DName FROM Device")
                .on('result', function (data) {
                    arr.push(data)
                })
                .on('end', function () {
                    return callback(null, arr);
                })
                .on('error', function (err) {
                    return callback(err, null);
                })
        });
    })
}

module.exports = {
    getDataFromDatabase
}

Call

var fromDB = require("./modulName");
var test = await fromDB.getDataFromDatabase();

Perhaps I made a mistake somewhere, I wrote from memory.
Here I wrote almost everything on asynchronous functions, maybe you will find something useful.