I am working with making a website using Nodejs, express and MySQL.

The problem I am facing is that with the way I am making my connection and queries to the database right now the connection is always connected so it times out in the end. I tried using Pools but I have a problem where when I want the connections to be called through a function and then return the results of the query so that I won't need to repeat the same code for each time I want to query that specific query.

Here is how I have it now where I create a connection and then whenever a function is called it would query the code and return the results of the query.

const mysql = require('promise-mysql');

let db;

(async function (err)
{
    db = await mysql.createConnection({
        host: dotenv.parsed.DB_HOST,
        user: dotenv.parsed.DB_LOGIN,
        password: dotenv.parsed.DB_PASSWORD,
        database: dotenv.parsed.DB_NAME,
        charset: dotenv.parsed.DB_CHAR,
        multipleStatements: dotenv.parsed.DB_MULTI
    });
    if (err){console.log(err);};
    process.on('exit', () => {db.end()});
})();

/**
* @description gets the user's personnumber and password
* @param {*} personnummer is the personal number issued by the Swedish government for the person in question 
*/
async function getPat(personnummer)
{
    let sql = "SELECT * FROM patients where personnummer=?";
    let res = await db.query(sql, [personnummer]);
    return res;
}

So how would I go about doing that in pools? because when I try to do that in a pool

const connection = mysql.createPool({
    host: dotenv.parsed.DB_HOST,
    user: dotenv.parsed.DB_LOGIN,
    password: dotenv.parsed.DB_PASSWORD,
    database: dotenv.parsed.DB_NAME,
    charset: dotenv.parsed.DB_CHAR,
    multipleStatements: dotenv.parsed.DB_MULTI
});

/**
* @description gets the user's personnumber and password
* @param {*} personnummer is the personal number issued by the Swedish government for the person in question 
*/
async function getPat(personnummer)
{
    let patient;
    (await connection).getConnection(function (err, connection)
    {
        if (err) throw err;
        connection.query("SELECT * FROM patient where personnummer=?", [personnummer], function (err, result)
        {
            if (err) throw err;
            patient = result;
        });
    });

    return patient;
}

What happens in the code above is inside the connection. query function there is results but as soon as we go out of it then the results are empty I can't seem to figure what the cause is.