Return query results from nested function in method

Question

I'm trying to store a query result from mysql using node into a variable and log that variable to the console. Because of the nested function within the method, I am not getting any returned results that are usable. I've tried several things to make this work but am looking for the most simple solution. Here's my code:

const mysql = require('mysql');
var billsSelectAllSQL = 'SELECT * FROM bills';

/* Start connection to MySQL */
var mysqlConnection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "password",
    database: "budget"
});

mysqlConnection.connect(function(err) {
    if(err) {
        throw err;
    }
    console.log("MySQL database connected!");
});

var mysqlQuery = function(query) {
    var queryResult;
    mysqlConnection.query(query, function(err, result, fields) {
        if(err) {
            throw err;
        }
        queryResult = result;
    });
    return queryResult;
};

var bills = mysqlQuery(billsSelectAllSQL);
console.log(bills);