Node.js で MySQL をクエリする際の同時実行性の問題を Async/Await で解決するにはどうすればよいですか?

// Original Code
var string1 = '';
var string2 = '';
var string3 = '';
var string4 = '';

DatabasePool.getConnection((err, connection) => {
  // Query 1
  connection.query(query, (err, result) => {
    string1 = result;
  });

  // Query 2
  connection.query(query, (err, result) => {
    string2 = result;
  });

  // Query 3
  connection.query(query, (err, result) => {
    string3 = result;
  });

  // Query 4
  connection.query(query, (err, result) => {
    string4 = result;
  });

  // Attempt to concatenate results
  var appended_text = string1 + string2 + string3 + string4;
});

// Improved Code
const mysql = require('mysql');
const util = require('util');
const conn = mysql.createConnection({ yourHOST, yourUSER, yourPW, yourDB });

// Promisify the query method
const query = util.promisify(conn.query).bind(conn);

(async () => {
  try {
    // Execute queries concurrently
    const [query1Result, query2Result, query3Result, query4Result] = await Promise.all([
      query('select count(*) as count from file_managed'),
      query('another query'),
      query('another query'),
      query('another query'),
    ]);

    // Concatenate results
    const appended_text = query1Result[0].count + query2Result[0].count + query3Result[0].count + query4Result[0].count;
  } finally {
    // Close the connection
    conn.end();
  }
})();