I have following code that connect nodejs to mysql. When I run it the first time it work the data print out to the page but when I refresh the page it tell 'This site can’t be reached' 'localhost refused to connect.' I don't understand why I can connect to server only the first time. I use url as localhost:3000/car
var express = require('express');
var app = express();
app.use(express.static(__dirname));
var mysql = require('mysql');
var connection = mysql.createConnection({
host : 'localhost',
user : 'joeM',
password : 'versus',
database : 'joe'
});
app.get('/car', function(req, res){
connection.connect();
connection.query('SELECT * FROM test1', function(err, rows, fields) {
if (err) throw err;
var print = '<ol>';
for( var i = 0; i<rows.length; i++){
print +=('<li>ID:' + rows[i].id + ' Brand:' + rows[i].brand +'</li>' );
}
print += '</ol>';
res.send(print);
connection.end();
});
});
app.listen(3000, function(){
console.log('Magic Happen at port: 3000');
});
dont use connection.connect(); in every request and set it out of request block
Related
I created node js express applications with express generator. I am trying to create table by executing database script called db.js . This script is located into database folder . I am able to run the server but when I tried to execute the script by using C:\Users\Khundokar Nirjor\Desktop\Nodejs Resources\shopping-cart\database>node db.js
C:\Users\Khundokar Nirjor\Desktop\Nodejs Resources\shopping-cart\database>
It is not able to create the table or inserting records.
Here is my app.js code .
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var expressHbs = require('express-handlebars');
var mysql = require('./database/db');
var app = express();
require('./database/db');
// view engine setup
app.engine('.hbs',expressHbs({defaultLayout: 'layout' , extname: '.hbs'}));
app.set('view engine', '.hbs');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', indexRouter);
//app.use('/users', usersRouter);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
module.exports = app;
Here is the db.js code .
var mysql = require('mysql');
//var app = express();
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "",
database: "shopdb"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
var sql = "CREATE TABLE products (imagepath VARCHAR(255), tittle VARCHAR(255), descriptions VARCHAR(255),price VARCHAR(255))";
var sql1 = "INSERT INTO products (imagepath, tittle,descriptions,price) VALUES ?";
var values = [
['https://upload.wikimedia.org/wikipedia/en/5/5e/Gothiccover.png', 'Gothic Veido Game','Awesome Game !!!!','25'],
['https://upload.wikimedia.org/wikipedia/en/5/5e/Gothiccover.png', 'Gothic Veido Game','Awesome Game old !!!!','100'],
['https://upload.wikimedia.org/wikipedia/en/5/5e/Gothiccover.png', 'Gothic Veido Game','Awesome Game New !!!!','120'],
['https://upload.wikimedia.org/wikipedia/en/5/5e/Gothiccover.png', 'Gothic Veido Game','Awesome Game !!!!','26'],
];
con.query(sql, sql1,[values], function (err, result) {
if (err) throw err;
console.log("Number of records inserted: " + result.affectedRows);
});
});
con.destroy();
You should enable multistatement true while creating a connection as you are running multiple statements.change your configuration options as below:
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "",
database: "shopdb",
multipleStatements: true
});
Refer this :
https://github.com/mysqljs/mysql#multiple-statement-queries
I have a form called #add_blog_post with the action "/mysql_test/add_blog_post" and method of "POST"
Jade markup:
form#add_blog_post(action="/mysql_test/add_blog_post" method="POST")
This form executes the following code in my app.js:
app.post('/mysql_test/add_blog_post', function(req, res) {
var author = req.body.author;
var date = req.body.date;
var title = req.body.title;
var body = req.body.body;
var blog_insert_query = "insert into 332project.blog(author,date,title,body) values(";
blog_insert_query += ("'"+author+"'"+","); blog_insert_query += ("'"+date+"'"+","); blog_insert_query += ("'"+title+"'"+","); blog_insert_query += ("'"+body+"'"+")");
var connection = mysql.createConnection({
host: process.env.DB_HOST,
user: process.env.DB_USER,
password: process.env.DB_PASS
});
connection.connect(function(err) { /*error?*/ });
var result;
var query = connection.query(blog_insert_query, function(err, result) {
res.redirect('/mysql_test');
});
});
The blog post insert works just fine but the website takes a while for the insert to be displayed from the select statement on /mysql_test.
Here is my route:
var express = require('express');
var router = express.Router();
var db_calls = require('../db.js');
var connection = db_calls.connect();
connection.connect(function(err) { /*error?*/ });
var result;
var query = connection.query("select * from 332project.blog order by id desc", function(err, rows, fields) {
connection.end();
if (!err) {
result = rows;
}
});
router.get('/', function(req, res, next) {
res.render('mysql_test', {
result: result
});
});
module.exports = router;
What gives? It almost seems like a caching issue. I'd really like for my create/update operations to be instantly visible in my application.
Source code: https://github.com/harwoodjp/learning-express
Your problem is probably that you're not calling connection.end() per the docs.
Hello i am trying to check two mysql values and if its matching anything in the database it needs to generate a token but it does not seem to work :(
Everytime i run this code i get a connection time out:
var express = require('express');
var router = express.Router();
var mysql = require("mysql");
var randomstring = require("randomstring");
/* GET users listing. */
router.get('/', function(req, res, next) {
// First you need to create a connection to the db
var connection = mysql.createConnection({
host: "localhost",
user: "segfault",
password: "wnk9ctte2endcKzBKtre7auE",
database: "segfault"
});
connection.connect();
var input_user = req.body.username;
var input_pass = req.body.password;
var token = randomstring.generate(12);
connection.query('SELECT username FROM segfault.users AS username', function(err, rows, fields) {
if (err) throw err;
for(var i in rows){
username = rows[i].username;
if(input_user == username){
connection.query('SELECT password FROM segfault.users AS password', function(err, rows, fields) {
if(rows[i].password == input_pass){
res.send("OK: "+ token);
console.log("OK:" + token)
}
});
}
}
});
connection.end();
});
module.exports = router;
tell me please what i am dooing wrong!
You close the connection to the database without waiting for the result of the query.
Move connection.end(); inside callback after the res.send.
I am new to node.js. How should I start a session when the user logs in and end the session when the user logs out?
Please note the environment of this application:
I'm using Windows
NPM, Express
MySQL for Node
This is my app.js file:
var express = require('express');
var routes = require('./routes');
var http = require('http');
var path = require('path');
var customers = require('./routes/customers');
var app = express();
var connection = require('express-myconnection');
var mysql = require('mysql');
app.set('port', process.env.PORT || 4300);
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
app.use(express.logger('dev'));
app.use(express.json());
app.use(express.urlencoded());
app.use(express.methodOverride());
app.use(express.static(path.join(__dirname, 'public')));
if ('development' == app.get('env')) {
app.use(express.errorHandler());
}
app.use(
connection(mysql,{
host: 'localhost',
user: 'root',
password : '',
//port : 3306, //port mysql
database:'nodejs'
},'pool') //or single
);
app.get('/', customers.login);
app.get('/login', customers.login);
app.post('/login', customers.checklogin);
app.get('/logout', customers.logout);
app.use(app.router);
http.createServer(app).listen(app.get('port'), function(){
console.log('Express server listening on port ' + app.get('port'));
});
And this is routing File (customers.js):
exports.logout = function(req, res){
var messages = '';
res.render('login',{page_title:"Login",message: messages});
};
exports.checklogin = function(req,res){
var loginInput = JSON.parse(JSON.stringify(req.body));
req.getConnection(function (err, connection) {
var username = loginInput.username;
var pswd = loginInput.pswd;
var query = connection.query("SELECT * FROM users WHERE username = ? AND pswd = ? ",[username,pswd], function(err,rows)
{
var messages = 'Username/Password is wrong. Try again.';
res.render('login',{page_title:"Login",message: messages});
});
});
};
It's really simple if you're using sessions.
app.post('/login', function(req, res, next) {
if(err) return next(err)
if(authenticate(req.body.username, req.body.password) req.session.user = {login: true, username: req.body.username }
res.render(<Some file you want to send to user>);
}
app.get('/logout', function(req, res, next) {
if(err) return next(err)
req.session.user = {login: false, username = null}
res.render(<Some file you want to send to user>);
This way you can login a user and set their username for later use in sessions and log them out in the same way.
I am new to Node an Express, I have this code which simply connects to a MySQL Db...Nothing is happening when I try to 127.0.0.1:9080. I'm doing something wrong but can't figure out what...nothing in the console no errors, tried in chrome, FF, Safari and IE...Any ideas.
var http = require('https');
var express = require('express');
var app = express();
var hbs = require('hbs');
var path = require('path');
var mysql = require('mysql');
app.set('view engine', 'html');
app.engine('html', hbs.__express);
//mysql connect
var connection = mysql.createConnection({
host : 'mysql://root#localhost/mydb2',
user : 'someone',
password : 'secret'
});
app.get('/', function(request, response) {
connection.query('select * from sometable', function(err, rows){
if (err) throw err;
console.log("Test01=" + row[0].toString());
});
app.listen(9080);
});
You need to write something in the response to see it on the browser.
Add this line before console.log() statement.
response.json(rows);