I have the following code in my db.js file:

const mysql2 = require('mysql2/promise');

// Connect to server (locally for development mode) ----- NEW VERSIN
const pool = mysql2.createPool({
    host     : "ENDPOINT",
    user     : "admin",
    password : "PASSWORD",
    port     : "3306",
    database : "DATABASE",
    waitForConnections: true,
    connectionLimit: 10,
    queueLimit: 0
});

module.exports = pool;

And in my app.js file I have:

const pool = require('./db');

async function checkUser(username) {
  const result = await pool.query('SELECT * from users WHERE username = ?', [username]);
  if (result[0].length < 1) {
    throw new Error('Row with this username was not found');
  }
  return result[0][0];
}

async function check() {
  let user = await checkUser("username");
  console.log(user);
}

check(); But I'm getting the error:

(node:42037) UnhandledPromiseRejectionWarning: TypeError: pool.query is not a function

This is weird, because when I run all the code in the db.js file it works fine, so I'm probably messed up the export/require bit of it, please help!

ANSWER: HOW TO EXPORT MULTIPLE FUNCTIONS

In the document you are exporting, write as follows:

  module.exports = {FunctionName1, FunctionName2, FunctionName3};

In the document you are importing to, write the following:

const {FunctionName1, FunctionName2, FunctionName3} = require('./whereyouareimportingfrom');