connection.query('insert into username (name) values ("msg")', function(err,    rows, fields) {

    if(!err) {


     } });

connection.query('insert into username (name) values '+ msg, function(err,    rows, fields) {

    if(!err) {


     } });

'insert into username (name) values hello world'

var util - require('util');
var mySql = util.format('insert into username (name) values ("%s")', 'hello world');
connection.query(mySql, function(err,    rows, fields) {

if(!err) {


 } });

const connection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'pass',
  database: 'db_name'
});

connection.query(`INSERT INTO user_table (name, mail, pass) VALUES ('${user_name}', '${user_name}', '${user_name}');`, function (err, result, fields) {
  if (err) throw err;
  });