How to fetch data from MySQL database with Node - mysql

Question

I'm new to react, developing a recipe-app and I got a problem while displaying the data from MySQL database. The connection was created successfully, however, I'm not sure about how to reach the data. When I run node server.js in my terminal, I get "connected", When I visit the localhost:8080/users, I get "This site can't be reached" message and in my terminal:
`events.js:187
throw er; // Unhandled 'error' event
^
Error: Cannot enqueue Handshake after already enqueuing a Handshake.`
I'm a little stuck here. Anyone knows a solution or direct me a little bit? Thank you so much!
Server.js
const express = require('express');
const app = express();
const PORT = 8080;
const mysql = require('mysql');
const connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: 'root',
database: 'recipe_app'
});
connection.connect((err) => {
if (err) throw err;
console.log('Connected!');
});
//creating route for the app
app.get('/users', (req, res) => {
connection.connect();
connection.query('SELECT * from users', function(err, rows, fields) {
if (!err) {
res.send(JSON.stringify(rows));
} else {
console.log('Error while performing Query.');
}
});
connection.end();
});
//making server listen to request
app.listen(PORT, () => {
console.log(`Server running at : http://localhost:${PORT}/`);
});

Answer 1

You're trying to reconnect to mysql after the connection has been established.
See my comments on the code below
const connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: 'root',
database: 'recipe_app'
});
connection.connect((err) => { // This creates the connection
if (err) throw err;
console.log('Connected!');
});
And when you're trying to resolve your GET routes, you're trying to connect again
//creating route for the app
app.get('/users', (req, res) => {
connection.connect(); // reconnect here
Since you're using the default connection method, trying to connect to an already established connection will cause the driver to throw a Handshake error.
If you want to re-use the connection, store it in a variable and then re-use it in other part of your code.
If you want to manage multiple connections instead, I suggest you to look at createPool instead.

Answer 2

Try removing the connection.connect() and connection.end() from app.get