Error: Cannot enqueue Handshake after invoking quit. How to fix?

Question

MySQL

The code:

var sql = require("mysql");
var connection = sql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'password',
    database: 'chat'
});

app.get('/', function(req, res) {
    connection.connect();
    var loga = "kulonful";
    connection.query('select * from users where login = "'+loga+'"', function(err, result){
        if(err) { connection.end(); res.send('Произошла критическая ошибка'); }
        connection.end();
        res.send(result);
    });
})

The first time everything is smooth, but if you refresh the page, an error is thrown in the console:

events.js:160 thrower
; // Unhandled 'error' event
^
Error: Cannot enqueue Handshake after invoking quit.
at Protocol._validateEnqueue (/root/node_modules/mysql/lib/protocol/Protocol.js:202:16)
at Protocol._enqueue (/root/node_modules/mysql/lib/protocol/Protocol.js:135:13)
at Protocol .handshake (/root/node_modules/mysql/lib/protocol/Protocol.js:52:41)
at Connection.connect (/root/node_modules/mysql/lib/Connection.js:130:18)
at /root/api. js:18:16
at Layer.handle [as handle_request] (/root/node_modules/express/lib/router/layer.js:82:5)
at next (/root/node_modules/express/lib/router/route.js :100:13)
at Route.dispatch (/root/node_modules/express/lib/router/route.js:81:3)
at Layer.handle [as handle_request] (/root/node_modules/express/lib/router/layer.js:82: 5)
at /root/node_modules/express/lib/router/index.js:235:24

What's wrong? Help)

Answer 1

The error occurs because the connection is terminated after the first request. It is necessary to do sql.createConnection again. But this is the wrong approach. The code needs to be rewritten.
Create a connection outside of the request and listen for the error event. If there is an error, break the connection and reconnect using createConnection.