MySQL Connection Pooling and Data Format for RHMAP Forms

wines.js

var express = require('express');
var bodyParser = require('body-parser');
var cors = require('cors');
var mysql      = require('mysql');

var pool      =    mysql.createPool({
  connectionLimit : 100, //important
  host     : process.env.MYSQL_HOST,
  user     : process.env.MYSQL_USERNAME,
  password : process.env.MYSQL_PASSWORD,
  database : "top100",
  charset: 'utf8_general_ci',
  debug    :  false
});

function handle_database(req,res) {
    pool.getConnection(function(err,connection){
        if (err) {
          connection.release();
          res.json({"code" : 100, "status" : "Error in connection database"});
          return;
        }   

        console.log('connected as id ' + connection.threadId);
        
          connection.query('SELECT id AS "key", winename AS "value" FROM wines', function(err, rows, fields) {
            connection.release();
            if(!err) {
              var result = [];
              for (var i = 0; i < rows.length; i++) {
                result.push({"key": rows[i].key, "value": rows[i].value, "selected": false});
              }
              res.header('Content-Type', 'application/json; charset=utf-8');
              res.json(result);
                      }           
                  });
        connection.on('error', function(err) {      
              res.json({"code" : 100, "status" : "Error in connection database"});
              return;     
        });
  });
}


function wineRoute() {
  var wine = new express.Router();
  wine.use(cors());
  wine.use(bodyParser());

  // GET REST endpoint - query params may or may not be populated
  wine.get('/', function(req, res) {
    handle_database(req,res);
  });

  return wine;
}

module.exports = wineRoute;

Output:

[{"key":1,"value":"Peter Michael Cabernet Sauvignon Oakville Au Paradis","selected":false},{"key":2,"value":"Quilceda Creek Cabernet Sauvignon Columbia Valley","selected":false},{"key":3,"value":"Evening Land Pinot Noir Eola-Amity Hills Seven Springs Vineyard La Source","selected":false},{"key":4,"value":"Il Poggione Brunello di Montalcino","selected":false},{"key":5,"value":"Mount Eden Vineyards Chardonnay Santa Cruz Mountains","selected":false},{"key":6,"value":"Bodegas Aalto Ribera del Duero","selected":false},{"key":7,"value":"Escarpment Pinot Noir Martinborough Kupe Single Vineyard","selected":false},{"key":8,"value":"Masi Amarone della Valpolicella Classico Serègo Alighieri Vaio Armaron","selected":false},{"key":9,"value":"Clos Fourtet St.-Emilion","selected":false},{"key":10,"value":"Klein Constantia Vin de Constance Constantia","selected":false},{"key":11,"value":"Big Table Farm Pinot Noir Willamette Valley","selected":false},{"key":12,"value":"Limerick Lane Zinfandel Russian River Valley","selected":false},{"key":13,"value":"La Serena Brunello di Montalcino","selected":false},{"key":14,"value":"Bergström Pinot Noir Ribbon Ridge Le Pré Du Col Vineyard","selected":false},{"key":15,"value":"Abadia Retuerta Viño de la Tierra de Castilla y León Sardon de Duero Selección Especial","selected":false},{"key":16,"value":"Taylor Fladgate Late Bottled Port","selected":false},{"key":17,"value":"Turley Petite Syrah Howell Mountain Rattlesnake Ridge","selected":false},{"key":18,"value":"Altesino Brunello di Montalcino Montosoli","selected":false},{"key":19,"value":"Dehlinger Pinot Noir Russian River Valley Altamont","selected":false},{"key":20,"value":"Meiomi Pinot Noir Monterey-Sonoma-Santa Barbara Counties","selected":false},{"key":21,"value":"Cloudy Bay Sauvignon Blanc Marlborough","selected":false},{"key":22,"value":"Gramercy Syrah Walla Walla Valley The Deuce","selected":false},{"key":23,"value":"Bodegas LAN Rioja Edición Limitada","selected":false},{"key":24,"value":"Blandy's Bual Madeira","selected":false},{"key":25,"value":"Quinta do Crasto Douro Superior","selected":false},{"key":26,"value":"Carpineto Vino Nobile di Montepulciano Riserva","selected":false},{"key":27,"value":"Livio Sassetti Brunello di Montalcino Pertimali","selected":false},{"key":28,"value":"Baer Ursa Columbia Valley","selected":false},{"key":29,"value":"Tenshen White Santa Barbara County","selected":false},{"key":30,"value":"Dominio de Tares Mencía Bierzo Cepas Viejas","selected":false},{"key":31,"value":"K The Creator Walla Walla Valley","selected":false},{"key":32,"value":"Viña Carmen Cabernet Sauvignon Maipo Valley Alto Gran Reserva","selected":false},{"key":33,"value":"Pewsey Vale Riesling Eden Valley Dry","selected":false},{"key":34,"value":"Tenet Syrah Columbia Valley The Pundit","selected":false},{"key":35,"value":"Rombauer Chardonnay Carneros","selected":false},{"key":36,"value":"Bodegas Godeval Valdeorras Viña Godeval Cepas Vellas","selected":false},{"key":37,"value":"Viña Montes Syrah Colchagua Valley Alpha","selected":false},{"key":38,"value":"Soléna Pinot Noir Willamette Valley Grande Cuvée","selected":false},{"key":39,"value":"Real Companhia Velha Douro Porca de Murça Red","selected":false},{"key":40,"value":"Pomelo Sauvignon Blanc California","selected":false},{"key":41,"value":"Podere Sapaio Bolgheri Volpolo","selected":false},{"key":42,"value":"Keplinger SUM? Amador County","selected":false},{"key":43,"value":"Collosorbo Brunello di Montalcino","selected":false},{"key":44,"value":"Piattelli Malbec Luján de Cuyo Premium Reserve","selected":false},{"key":45,"value":"Colene Clemens Pinot Noir Chehalem Mountains Margo","selected":false},{"key":46,"value":"Castello d'Albola Chianti Classico","selected":false},{"key":47,"value":"Jean-Marc Brocard Chablis Ste.-Claire","selected":false},{"key":48,"value":"Calera Chardonnay Central Coast","selected":false},{"key":49,"value":"Felton Road Pinot Noir Central Otago Bannockburn","selected":false},{"key":50,"value":"Bartolo Mascarello Barolo","selected":false},{"key":51,"value":"Alain Brumont Madiran Château Bouscassé","selected":false},{"key":52,"value":"Brancaia Toscana Ilatraia","selected":false},{"key":53,"value":"Descendientes de J. Palacios Bierzo Pétalos","selected":false},{"key":54,"value":"Kumeu River Chardonnay Kumeu Estate","selected":false},{"key":55,"value":"Arcanum Toscana Il Fauno","selected":false},{"key":56,"value":"Cune Rioja Imperial Reserva","selected":false},{"key":57,"value":"Altamura Cabernet Sauvignon Napa Valley","selected":false},{"key":58,"value":"Torre de Oña Rioja Finca San Martín Crianza","selected":false},{"key":59,"value":"Rodney Strong Cabernet Sauvignon Alexander Valley Rockaway Single Vineyard","selected":false},{"key":60,"value":"Roederer Estate Brut Anderson Valley L'Ermitage","selected":false},{"key":61,"value":"Clarendon Hills Grenache Clarendon Romas","selected":false},{"key":62,"value":"Oddero Barolo","selected":false},{"key":63,"value":"Mulderbosch Chenin Blanc Stellenbosch W Block","selected":false},{"key":64,"value":"Grapes of Roth Merlot Long Island","selected":false},{"key":65,"value":"Chappellet Cabernet Sauvignon Napa Valley Signature","selected":false},{"key":66,"value":"Domaine Terlato & Chapoutier Shiraz-Viognier Victoria","selected":false},{"key":67,"value":"Feudo di Santa Croce Primitivo di Manduria LXXIV","selected":false},{"key":68,"value":"Booker Syrah Paso Robles Fracture","selected":false},{"key":69,"value":"Bodegas Monasterio Ribera del Duero Hacienda Monasterio","selected":false},{"key":70,"value":"Allram Grüner Veltliner Qualitätswein Trocken Kamptal Hasel Alte Reben Reserve","selected":false},{"key":71,"value":"Antinori Bolgheri Superiore Guado al Tasso","selected":false},{"key":72,"value":"Lavau Gigondas","selected":false},{"key":73,"value":"Alpha Estate Malagouzia Florina Turtles Vineyard","selected":false},{"key":74,"value":"d'Angelo Aglianico del Vulture","selected":false},{"key":75,"value":"Domaine Tempier Bandol Rosé","selected":false},{"key":76,"value":"Leeuwin Chardonnay Margaret River Art Series","selected":false},{"key":77,"value":"M. Chapoutier Hermitage White Chante-Alouette","selected":false},{"key":78,"value":"Chateau St. Jean Cabernet Sauvignon Alexander Valley","selected":false},{"key":79,"value":"Bérêche & Fils Brut Champagne Réserve","selected":false},{"key":80,"value":"Bodegas Marqués de Murrieta Viura Rioja Capellanía","selected":false},{"key":81,"value":"Bodega Luigi Bosca Malbec Luján de Cuyo Single Vineyard","selected":false},{"key":82,"value":"Viña Polkura Syrah Marchigue","selected":false},{"key":83,"value":"Torre Rosazza Pinot Grigio Friuli Colli Orientali","selected":false},{"key":84,"value":"Duorum Douro","selected":false},{"key":85,"value":"Hecht & Bannier Côtes du Roussillon-Villages","selected":false},{"key":86,"value":"Ravines Riesling Finger Lakes Dry Argetsinger Vineyard","selected":false},{"key":87,"value":"Tenuta delle Terre Nere Etna","selected":false},{"key":88,"value":"Viña Koyle Cabernet Sauvignon Colchagua Valley Royale Los Lingues Vineyard","selected":false},{"key":89,"value":"Zisola Sicilia","selected":false},{"key":90,"value":"Philippe Alliet Chinon","selected":false},{"key":91,"value":"Schloss Vollrads Riesling Spätlese Rheingau","selected":false},{"key":92,"value":"Rotem & Mounir Saouma Châteauneuf-du-Pape Omnia","selected":false},{"key":93,"value":"Schola Sarmenti Nardò Nerìo Riserva","selected":false},{"key":94,"value":"Domaine du Gros Noré Bandol","selected":false},{"key":95,"value":"Grosset Riesling Clare Valley Springvale","selected":false},{"key":96,"value":"Bouchard Père & Fils Beaune Teurons Domaine","selected":false},{"key":97,"value":"Orin Swift Machete California","selected":false},{"key":98,"value":"Château Figeac St.-Emilion","selected":false},{"key":99,"value":"Jean-François Ganevat Côtes du Jura Les Chamois du Paradis","selected":false},{"key":100,"value":"Sadie Family Palladius Swartland","selected":false}]