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"
}
Related
I've tried following the suggestion at this link: MySQL 8.0 - Client does not support authentication protocol requested by server; consider upgrading MySQL client
and am aware that it is using cahcing_sha2_password instead of mysql_native. However, I've tried following the suggestions and am still receiving the same errors, trying to connect to the database with node.
Schema name: 'my_db'
//DATABASE CONNECTION SETTINGS
const APIServerPort = 3001;
const database = {
host: "localhost",
port: 3306,
user: "root",
password: "xxx",
database: "my_db"
};
module.exports = {
database,
APIServerPort
};
app.js file:
const express = require("express");
const app = express();
const router = express.Router();
const settings = require("./settings");
const routes = require("./routes");
const mysql = require("mysql");
const connection = mysql.createConnection(settings.database);
router.get("/employees", routes.employees.listAllEmployees);
app.use("/apis", router);
connection.connect(error => {
if (error) {
console.error("Error Connecting to the database: " + error);
return process.exit();
}
app.listen(settings.APIServerPort, () =>
console.info(`Server is running at port ${settings.APIServerPort}...`)
);
});
SQL Queries Ran:
CREATE USER 'root'#'localhost:3301/apis/employees' IDENTIFIED WITH mysql_native_password BY 'xxx';
FLUSH PRIVILEGES;
I'm still receiving the same error however.
mysql users are in the form 'root'#'localhost'. Urls are a node.js concept only.
As that user already exists create a new one:
CREATE USER myapplication#localhost
IDENTIFIED WITH mysql_native_password BY 'xxx';
GRANT ALL ON my_db.* TO myapplication#localhost`;
You don't need FLUSH PRIVILEGES.
I am using Angular 2 and Nodejs to Connect to an SQL Server. If I simply put following code in a js file and run it through the console using node test.js the code deletes the record properly.
Here is the code:
var webconfig = {
user: 'sa',
password: 'test',
server: 'localhost',
database: 'Test',
options: {
encrypt: false // Use this if you're on Windows Azure
}
}
var express = require('express');
var sql = require('mssql');
var http = require('http');
var app = express();
var port = process.env.PORT || 4200;
var connection = new sql.Connection(webconfig, function(err) {
var request = new sql.Request(connection);
request.query('delete from Employee where Id = 2382', function(err, recordset) {
if(err) // ... error checks
console.log('Database connection error');
console.dir("User Data: "+recordset);
});
});
app.listen(port);
console.log(port+' is the magic port');
After that I moved the same file to the src folder in my Angular 2 project (where the index.html file also exists). I put the same code into a function in test.js file like that:
function testConnection()
{
var webconfig = {
user: 'sa',
password: 'test',
server: 'localhost',
database: 'Test',
options: {
encrypt: false // Use this if you're on Windows Azure
}
}
var express = require('express');
var sql = require('mssql');
var http = require('http');
var app = express();
var port = process.env.PORT || 4200;
var connection = new sql.Connection(webconfig, function(err) {
var request = new sql.Request(connection);
request.query('delete from Employee where Id = 2382', function(err, recordset) {
if(err) // ... error checks
console.log('Database connection error');
console.dir("User Data: "+recordset);
});
});
app.listen(port);
console.log(port+' is the magic port');
}
Now I want to call testConnection() from the index page. I have put the <script src="C:\Users\amandeep.singh\Desktop\Angular\my-app\src\test.js"> to script path and call the function using this:
<script>
testConnection();
</script>
The index page executes properly but doesn't show any error nor executes the command. I'm unable to understand why the same code works in the console on Nodejs but not in my index.html.
Help will be appreciated.
You can't run Node applications in the browser. Nodejs is an application that runs Javascript in Google's V8 Javascript VM on your operating system and is meant to be a backend system (at least in the web development stack).
So you basically have to run your Node program on a webserver and make your API requests from the Angular application.
There are several tutorials out there on the internet that help you with this.
Here is the official Angular documentation angular.io
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
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});
I'm getting really confused over how to connect to MongoLab on Heroku.
To connect using the uri to Heroku, I was trying to follow this example:
http://experiencecraftsmanship.wordpress.com/2012/01/06/heroku-node-js-mongodb-featuring-the-native-driver/
I looked at both his web.js and deep.js.
They both do something like:
connect.createServer(
require( 'connect-jsonrpc' )( contacts )
).listen( port );
But then only the database query in 'contacts' get passed into this server then?
Am I allowed to do multiple connect.createServer for each of my database access method?
The following is part of my code when just connecting to MongoDB locally. I am unsure of how to modify it to connect to MongoLab on Heroku.
Can someone teach me how to modify my code to connect? Or explain some of these concepts? I have no idea why the author of that website I posted used so many callbacks to do a database call, when my approach below seems straightforward enough (I'm new to JavaScript, not good with callbacks).
var app = module.exports = express.createServer(
form({ keepExtensions: true })
);
var Db = require('mongodb').Db;
var Server = require('mongodb').Server;
var client = new Db('blog', new Server('127.0.0.1', 27017, {}));
var posts;
var getAllPosts = function(err, collection) {
collection.find().toArray(function(err, results) {
posts = results;
console.log(results);
client.close();
});
}
app.get('/', function(req, response) {
client.open(function(err, pClient) {
client.collection('posts', getAllPosts);
});
// some code
response.render('layout', { posts: posts, title: 'Raymond', contentPage: 'blog' });
});
You connect to your mongolab database (so you can't create a new "blog" database). process.env.MONGOLAB_URI includes the database name as well. See your mongolab uri:
heroku config | grep MONGOLAB_URI
It looks like: mongodb://heroku_app123456:password#dbh73.mongolab.com:27737/heroku_app123456
On github there is an example how to connect and retrieve data from a mongolab database.
Use "connect" to connect to mongo, instead of defining db, server, client:
var connect = require('connect');
var mongo = require('mongodb');
var database = null;
var mongostr = [YOUR MONGOLAB_URI];
mongo.connect(mongostr, {}, function(error, db)
{
console.log("connected, db: " + db);
database = db;
database.addListener("error", function(error){
console.log("Error connecting to MongoLab");
});
});