connection with dynamic database node.js using exports

Question

I am getting the database name from front end when user logged in the system and I have to make the connection with that database for further process.I am able to do it if create the connection on same page but I want to use 'exports' I am trying this. I am new in node.js so if there is some very silly mistake please dont mind and help me to understand. I tried different way of exporting but not able to make it run.

my DB_dynamic.js:

var mysql = require('mysql');
exports.dynamicConnection= function(dbname){
var connection = mysql.createConnection({
  host: process.env.DBHost || 'localhost',
  port: process.env.DBPort || 3306,
  user: process.env.DBUser || 'root',
  password: process.env.DBPassword || '',
  database: process.env.DBName || dbname
});
connection.connect((err) =>{
  if(err) throw err;
  console.log('Mysql Connected...');
});
}

now in my model.js

var new_conn = require('./DB_dynamic.js');
var conn = new_conn.dynamicConnection(dbname);
  conn.query("my query"); //Error!

Error:

TypeError: Cannot read property 'query' of undefined

Answer 1

DB_dynamic.js

const mysql = require('mysql');


module.exports = dbConnection = (dbname) => {
    return connection = mysql.createConnection({
        host: process.env.DBHost || 'localhost',
        port: process.env.DBPort || 3306,
        user: process.env.DBUser || 'root',
        password: process.env.DBPassword || '',
        database: process.env.DBName || dbname
    });
};

model.js

let dbConnection = require('./DB_dynamic.js');

console.log(dbConnection("your_db_name").query("your_query"))

Answer 2

module .exports.dynamicConnection = function（dbname）{