How to hang a promise on sqlite methods and is a promise needed?

Question

JavaScript

I think it's easier to give an example of the code and its current result, and a description of the desired result.

Database

'use strict';

class Database {

    constructor() {
        this._sqlite3 = require('sqlite3').verbose();
        this._conn = new this._sqlite3.Database(__dirname + '/database.sqlite');
    }


    findOne(sql, params) {
        let self = this;
        return self._conn.get(sql, params, function (err, row) {
            if(err) throw err;
            console.log(row);
            return row;
        })
    }

user

'use strict';

class User extends Database {
    constructor() {
        super();
    }

   getWorker() {
       let sql = 'select u.*, w.password from users u, workers w where u.id = w.user_id and u.type_id = ?';
       return super.findOne(sql, [1]);
   }

}

Page initialization

let user = new User();
console.log(user.getWorker()); // Приходит объект Database, хотя ожидаю Object просто

At first comes Database when pulled getWorker and only then Object with the User.