I’ve recently started learning javascript and I’m having a big problem understanding the async behavior of the language. I’ve spent hundreds of hours searching and everyone recommends the use of promises but I can’t quite comprehend what I’m doing wrong (maybe all of it lol).

I tried with promises as recommended by almost everyone in every forum and came up with this code but somehow I can’t manage to make it wait for function1 to be finished in function2, since I get that promise1 is undefined.

` async function function1() {
let query = “SELECT * FROM table1”;

    connection.query(query, (error, result) => {
        if (error) throw error;
        console.log("Length " result.rows.length);

        let result_query = [];
        let i = 0;
        while (i < result.rows.length) {
            result_query.push(result.rows[i]);
            i++;
        }

    let customPromise = new Promise((resolve, reject) => {
        if(result_query.length > 0){
            resolve(result_query);
        } else {
            reject(new Error('ERROR'))
        }
        });
    customPromise.then(() => {
        return customPromise;
    });
};

async function function2() {
    promise1 =  await function1();
    promise1.then(function(){ //HERE I GET THAT PROMISE1 IS UNDEFINED
        console.log("Exit");
    })
}`

This is my original code where I realized javascript has an asynchronous nature and it prints “Exit” in function2 before function1 is finished. I’m sorry if this is an obvious question but I feel stuck. Thank you all for your kindness in helping strangers.

` async function function1() {
let query = “SELECT * FROM table1”;

    connection.query(query, (error, result) => {
        if (error) throw error;
        console.log("Length " result.rows.length); //*THIS PRINTS AFTER THE EXIT IN FUNCTION2

        let result_query = [];
        let i = 0;
        while (i < result.rows.length) {
            result_query.push(result.rows[i]);
            i++;
    }

    if(result_query.length > 0){
        return(result_query);
    } else {
        return("ERROR");
    }
};

async function function2() {
    function1();
    console.log("Exit"); //*THIS PRINTS BEFORE EVERYTHING
}

OUTPUT:
Exit
Length 2`