My code:
var mysql = require('mysql');
var connection = mysql.createConnection({
host : '192.168.2.20',
user : 'test',
password : '123123123',
database : 'dbtest',
});
connection.connect(function(err) {
// connected! (unless `err` is set)
});
var query = connection.query('INSERT INTO posts (title) VALUES("data1");');
Everytime I run this SELECT * FROM dbtest.posts; using MySQL Workbench I never see any changes or results.
What am I doing wrong that NodeJS using mysql-node is not correctly editing my DB?
EDIT:
admin$ node debug test.js
< debugger listening on port 5858
connecting... ok
break in test.js:1
1 var mysql = require('mysql');
2 var connection = mysql.createConnection({
3 host : '192.168.2.20',
debug>
Do I have a problem in calling my files? They are kept under node_modules and the file is in the same root directory as node_modules
You are not being able to insert data with the code in your example probably because your MySQL server is with the autocommit system variable set to false.
What you can do in this case is to set this variable to true (see de docs) or change your code to force the commit, like:
connection.query('INSERT INTO posts (title) VALUES("data1");', function(err, result) {
if (err) {
connection.rollback(function () {
throw err;
});
}
connection.commit(function (err) {
if (err) {
connection.rollback(function () {
throw err;
});
}
console.log('Commited!');
});
});
Related
I'm very new to coding servers and javascript in general but I'm currently trying to set up a REST api server and connect it to my sql database, for the moment I am doing everything locally. I am running ubuntu 18.04 while using NODE js. I have been able to successfully create a REST api and connect to it through an url of a webpage or with Postman. I have created a sql server database through my cmd terminal and have created test data on it. I've been looking at guides to connect the REST api to the database but I think the info I'm giving the api to connect is where my issue is occurring. I am starting with this below as my server.js where i have a folder Controller and a ProductController.js file where I'm handling the route /api/products .
var http = require('http');
var express = require('express');
var app = express();
var port = process.env.port || 3000;
var productController = require('./Controller/ProductController')();
app.use("/api/products", productController);
app.listen(port, function(){
var datetime = new Date();
var message = "Server running on Port:- " + port + " Started at :- " +
datetime;
console.log(message);
});
Below is my ProductController.js file. The issue might be here but I believe it is my next file called connect.js the table in my sql database is called 'data' hence the "SELECT * FROM data" part. when I try to GET this data in postman it displays the error i set up "Error while inserting data". so I believe when running I'm not getting data from sql so conn.close() is not being reached.
var express = require('express');
var router = express.Router();
var sql = require("mssql");
var conn = require("../connection/connect")();
var routes = function()
{
router.route('/')
.get(function(req, res)
{
conn.connect().then(function()
{
var sqlQuery = "SELECT * FROM data";
var req = new sql.Request(conn);
req.query(sqlQuery).then(function (recordset)
{
res.json(recordset.recordset);
conn.close();
})
.catch(function (err) {
conn.close();
res.status(400).send("Error while inserting data");
});
})
.catch(function (err) {
conn.close();
res.status(400).send("Error while inserting data");
});
});
return router;
};
module.exports = routes;
This is my connect.js file below. I have a password for root which is not *** but is correct on my machine. I have changed root's plug in to mysql_native_password in the mysql terminal. I think the server: part is wrong, I've tried commenting it out but still no connection. I do not have SQL Server Management Studio and have not found a way to get my sql server's name through the terminal. I've seen examples that seem to range of what info you need to give the api to connect. If someone has insight on that too that would be appreciated as well. My end goal is to eventually create GET and POST routes for the database and a function to manipulate the POST data but for now I'm just trying to get things connected so I can play around with the data being GET'ed. Thanks for any insight you can give, it is much appreciated.
var sql = require("mssql");
var connect = function()
{
var conn = new sql.ConnectionPool({
host: 'localhost'
user: 'root',
password: '********',
server: 'mysql',
database: 'test'
});
return conn;
};
Looks like you may have some errors in your connect.js file:
var conn = new sql.ConnectionPool({
host: 'localhost'
user: 'root',
password: '********',
server: 'mysql',
database: 'test'
});
should be in the format of:
const pool = new sql.ConnectionPool({
user: '...',
password: '...',
server: 'localhost',
database: '...'
})
Note that you currently have both host and server, looks like only server is needed. Also, server: 'mysql' doesn't make sense if you are connecting to a MSSQL database.
Source: node-mssql documentation
To diagnose the errors you should add some logging to your catch blocks:
.catch(function (err) {
console.log('connection error', err); //or Bunyan, Winston, Morgan, etc. logging library
conn.close();
let message = "Error while inserting data"
if (process.env.NODE_ENV === 'development') { //conditionally add error to result message
message += "\n"+err.toString());
}
res.status(500).send(message); //use 5xx for server problems, 4xx for things a user could potentially fix
});
And set NODE_ENV in your environment, for example in package.json:
"scripts": {
"start": "NODE_ENV=production node app.js"
"start-dev": "NODE_ENV=development node app.js"
}
At the moment, I develop a node.js REST webservice with express. I used MongoDB + Mongoose to establish a database.
Now, I have the problem, that I can only use the db connection in the file where I established the connection. I found a solution to use the connection also in other files by "module.exports" the _db variable. But I don't know, if this is the best practise. Here is my code:
databaseManager.js
// Establish a connection to the database.
mongoose.Promise = global.Promise
mongoose.connect('mongodb://'+cfg.db.ip+':'+cfg.db.port+'/'+cfg.db.name)
var _db = mongoose.connection
_db.on('error', console.error.bind(console, 'DB connection error'))
_db.once('open', function()
{
console.log("DatabaseM: Connected to the database")
})
[...]
module.exports =
{
db : _db,
}
otherFile.js
var database = require('./databaseManagement')
[...]
database.db.collection('users').findOne({ name: "ashton"}, function(err, user)
{
if (err) return callback(consts.ERROR_DB, null)
if (!user) return callback(consts.WARN_DB_NO_CLIENT)
callback(null, user)
})
It works great. But there may be a risk that I do not see?
Thanks a lot :-)
In your app.js file :
var url="mongdb:\\localhost:27017\dbname";
mongoose.connect(url); //it open default connection for mongodb and is handled by mongoose
Now perform all your task whatever you want :
mongoose.connection.on('connected', function () {
console.log('Mongoose default connection open to ' + dbURI);
});
Bring all your database model in app.js file like as such:
var model1 = require('./models/model1');
model1.js
var mongoose = require('mongoose');
var data = new mongoose.Schema({
name:{type:String, required:true}
});
module.exports = mongoose.model('collectionName', data);
Now, when all your tasks are over. Simply close default connection like this :
mongoose.connection.on('disconnected', function () {
console.log('Mongoose default connection disconnected');
});
If any error occurs in connection handle it like this :
mongoose.connection.on('error',function (err) {
console.log('Mongoose default connection error: ' + err);
});
If node service exits then close connection usig this code
process.on('SIGINT', function() {
mongoose.connection.close(function () {
console.log('Mongoose default connection disconnected through app termination');
process.exit(0);
});
});
I'm having serious issues with an app I am building with Node.js, Express, MongoDB and Mongoose. Last night everything seemed to work when I used nodemon server.js to `run the server. On the command line everything seems to be working but on the browser (in particular Chrome) I get the following error: No data received ERR_EMPTY_RESPONSE. I've tried other Node projects on my machine and they too are struggling to work. I did a npm update last night in order to update my modules because of another error I was getting from MongoDB/Mongoose { [Error: Cannot find module '../build/Release/bson'] code: 'MODULE_NOT_FOUND'}. I used the solution in this answer to try and fix it and it didn't work and I still get that error. Now I don't get any files at all being served to my browser. My code is below. Please help:
//grab express and Mongoose
var express = require('express');
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
//create an express app
var app = express();
app.use(express.static('/public/css', {"root": __dirname}));
//create a database
mongoose.connect('mongodb://localhost/__dirname');
//connect to the data store on the set up the database
var db = mongoose.connection;
//Create a model which connects to the schema and entries collection in the __dirname database
var Entry = mongoose.model("Entry", new Schema({date: 'date', link: 'string'}), "entries");
mongoose.connection.on("open", function() {
console.log("mongodb is connected!");
});
//start the server on the port 8080
app.listen(8080);
//The routes
//The route for getting data for the database
app.get("/database", function(req, res) {
Entry.find({}, function(err, data) {console.log(err, data, data.length); });
});
//The route for posting data on the database
app.post("/database", function(req, res) {
//test new post
var newMonth = new Entry({date: '1997-10-30', link: 'https://wwww.youtube.com/'});
newMonth.save(function(err) {
if (err !== null) {
//object was not save
console.log(err);
} else {
console.log("it was saved!")
};
});
});
//create an express route for the home page at http://localhost:8080/
app.get('/', function(req, res) {
res.send('ok');
res.sendFile('/views/index.html', {"root": __dirname + ''});
});
//Send a message to the console
console.log('The server has started');
//The route for getting data for the database
app.get("/database", function(req, res) {
Entry.find({}, function(err, data) {console.log(err, data, data.length); });
});
//The route for posting data on the database
app.post("/database", function(req, res) {
//test new post
var newMonth = new Entry({date: '1997-10-30', link: 'https://wwww.youtube.com/'});
newMonth.save(function(err) {
if (err !== null) {
//object was not save
console.log(err);
} else {
console.log("it was saved!")
};
});
});
These routes don't send anything back to the client via res. The bson error isn't a big deal - it's just telling you it can't use the C++ bson parser and instead is using the native JS one.
A fix could be:
//The route for getting data for the database
app.get("/database", function(req, res) {
Entry.find({}, function(err, data) {
if (err) {
res.status(404).json({"error":"not found","err":err});
return;
}
res.json(data);
});
});
//The route for posting data on the database
app.post("/database", function(req, res) {
//test new post
var newMonth = new Entry({date: '1997-10-30', link: 'https://wwww.youtube.com/'});
newMonth.save(function(err) {
if (err !== null) {
res.status(500).json({ error: "save failed", err: err});
return;
} else {
res.status(201).json(newMonth);
};
});
});
updated june 2020
ERR_EMPTY_RESPONSE express js
package.json
"cors": "^2.8.4",
"csurf": "^1.9.0",
"express": "^4.15.4",
this error show when you try to access with the wrong HTTP request. check first your request was correct
maybe your cors parameter wrong
I'm wondering how to use the module node-mysql correctly in Node.js (using Express.js). I have a main router with this:
var Post = require('./models/post.js');
app.get('/archives', function (req, res) {
Post.findArchives(function(posts, err) {
if(err)
res.send('404 Not found', 404);
else
res.render('archives', { posts: posts});
});
});
And here's the content of the file post.js:
var mysql = require('mysql');
var dbURL = 'mysql://root#localhost/mydatabase';
exports.findArchives = function(callback) {
var connection = mysql.createConnection(dbURL);
connection.query('SELECT * FROM blog_posts_view WHERE status != 0 ORDER BY date DESC', function(err, rows) {
if(err) throw err
callback(rows, err);
connection.end();
});
};
How can I improve it? Improve the error handling? Also, there's the function handleDisconnect(connection); on their Github (https://github.com/felixge/node-mysql) that I'm not really sure how to integrate to make sure that the application will not crash when the database is not responding.
Thanks!
Take a look at the mysql-simple library. It combines node-mysql with a pooling library to create a connection pool, and also includes the code to handle the disconnects.
If you want to make it super easy, you could just use that module.
First question here, so be kind ;)
I am configuring a Node.js server to connect to a MongoDB database in Modulus.io node.js hosting (really good stuff, worth checking it out), but I can't seem to properly stablish connection. Per the getting-started guide I get a connection uri in the format:
mongodb://user:pass#mongo.onmodulus.net:27017/3xam913
But that doesn't seem to work with the structure of the code I was trying to port to the server (had it running locally) because of the Server class argument structure with only host and port to define...
This is the code I am trying to adapt to the connection:
// server setup
var mongo = require('mongodb'),
mdbServer = mongo.Server,
mdbDb = mongo.Db,
mdbObjectID = mongo.ObjectID;
// open a connection to the mongoDB server
var mdbserver = new mdbServer('localhost', 27017, {auto_reconnect: true});
// request or create a database called "spots03"
var db = new mdbDb('spots03', mdbserver, {safe: true});
// global var that will hold the spots collection
var spotsCol = null;
// open the database
db.open(function(err, db) {
if(!err) {
// if all cool
console.log("Database connection successful");
// open (get/create) a collection named spotsCollection, and if 200,
// point it to the global spotsCol
db.createCollection(
'spotsCollection',
{safe: false}, // if col exists, get the existing one
function(err, collection) {spotsCol = collection;}
);
}
});
Any help would be much appreciated, thanks!
Looks like a couple of things:
The connection URL should be mongo.onmodulus.net
var mdbserver = new mdbServer('mongo.onmodulus.net', 27017, {auto_reconnect: true});
rounce is correct, the database name is auto-generated by Modulus.
var db = new mdbDb('3xam913', mdbserver, {safe: true});
Modulus databases will need authentication. Before you call createCollection, you'll have to call auth and pass it the user credentials that are setup on the project dashboard.
I'm a Modulus developer, and I know the DB name thing is not ideal.
Edit: here's full source for a working example. It records every HTTP request and then sends all requests back to the user.
var express = require('express'),
mongo = require('mongodb'),
Server = mongo.Server,
Db = mongo.Db;
var app = express();
var server = new Server('mongo.onmodulus.net', 27017, { auto_reconnect: true });
var client = new Db('piri3niR', server, { w: 0 });
client.open(function(err, result) {
client.authenticate('MyUser', 'MyPass', function(err, result) {
if(!err) {
console.log('Mongo Authenticated. Starting Server on port ' + (process.env.PORT || 8080));
app.listen(process.env.PORT || 8080);
}
else {
console.log(err);
}
});
});
app.get('/*', function(req, res) {
client.collection('hits', function(err, collection) {
collection.save({ hit: req.url });
// Wait a second then print all hits.
setTimeout(function() {
collection.find(function(err, cursor) {
cursor.toArray(function(err, results) {
res.send(results);
});
});
}, 1000)
});
});
Wrong database name perhaps?
From the MongoDB docs on the subject '3xam913' is your database name, not 'spots03'.
var db = new mdbDb('3xam913', mdbserver, {safe: true});