Как правильно сделать запрос на mysql через nodejs?

let first_name = req.body.first_name;
let last_name = req.body.last_name;
let number = req.body.number;
let auto = req.body.auto;
let info = req.body.info;
let price = req.body.price;
let usernameQuery = "SELECT * FROM `ann` WHERE first_name = '" + first_name + "'";
db.query("INSERT INTO `ann` (first_name, last_name, number, info, price, auto) VALUES ('" + first_name + "', '" + last_name + "', '" + number + "', '" + info + "', '" + price + "', '" + auto + "')", function(err, info) {
  console.log(info.insertId);
});

В базе данных после отправки запроса в полях появляются undefined.