How to create an unused database ID with node.js - mysql

Question

I want to create an ID for my program. The ID is random, but I must make sure that it not already exists in database. To do so, I search the ID, and if the search result is empty, then the ID passes, but if the search finds something, the process needs to start over.
In PHP I can do this logic for my code:
require('somesqlconnection.php');
$repeat = false;
do {
$id = createId(50); // this is my function for creating random with 50 as length for the string
$result = mysqli_query("SELECT * FROM users WHERE id = '$id'", $conn);
$repeat = mysqli_num_rows($result) > 0;
} while ($repeat);
echo $id;
How can I implement the same logic in node.js that is basically executing in asynchronous?
I tried this but didn't work:
const util = require('util');
const sql = require('../sqlconnection.js');
let repeat = false;
const query = util.promisify(sql.query).bind(sql);
do {
let id = createId(50);
(async () => {
const rows = await query(`SELECT id FROM users WHERE id = '${id}'`);
repeat = rows.length > 0;
})();
} while(repeat);
console.log(id);

Answer 1

You could create a function that returns a promise for a new ID like this:
const util = require('util');
const sql = require('../sqlconnection.js');
sql.queryAsync = util.promisify(sql.query);
async function createNewId() {
const newId = createId(50);
const result = await sql.queryAsync('SELECT id FROM users WHERE id = ?', [newId]);
return !result.length ? newId : createNewId();
}
This returns the new ID, or it calls itself again.
Usage is either with .then():
createNewId().then(newId => {
console.log('found unused ID', newId);
// do something with it
}).catch(err => {
console.log('oops', err);
});
or inside an async function with await:
async function main() {
try {
const newId = await createNewId();
console.log('found unused ID', newId);
// do something with it
} catch (err) {
console.log('oops', err);
}
}