I am trying to set an API. when the default route is called, with '/', the route can be called several times but the route '/count' can only be called once before crashing with this error:
/Users/node_modules/mysql/lib/protocol/Parser.js:437
throw err; // Rethrow non-MySQL errors
^
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at ServerResponse.setHeader (_http_outgoing.js:467:11)
at ServerResponse.header (/Users/node_modules/express/lib/response.js:771:10)
at ServerResponse.send (/Users/node_modules/express/lib/response.js:170:12)
at ServerResponse.json (/Users/node_modules/express/lib/response.js:267:15)
at ServerResponse.send (/Users/node_modules/express/lib/response.js:158:21)
at Query.<anonymous> (/Users/server_sql/testingAPI/routes/index.js:25:36)
at Query.<anonymous> (/Users/node_modules/mysql/lib/Connection.js:525:10)
at Query._callback (/Users/node_modules/mysql/lib/Connection.js:491:16)
at Query.Sequence.end (/Users/node_modules/mysql/lib/protocol/sequences/Sequence.js:83:24)
at Query._handleFinalResultPacket (/Users/node_modules/mysql/lib/protocol/sequences/Query.js:139:8)
app.js
const http = require('http');
const cors = require('cors');
const body_parser = require('body-parser');
const databases = require('./connection_management');
const route = require('./routes/index');
const app = express();
app.use(cors());
app.use(body_parser.urlencoded({
extended: true
}));
app.use(body_parser.json());
app.use(databases.connectionsSql);
app.use('/', route);
http.createServer(app).listen(8080, (err) => {
if (!err)
console.log("API ready and HTTP listen on port 8080.");
else
console.log(err)
});
module.exports = app;
route/index.js
var router = require('express').Router();
var connection = require('../connection_management');
router.get('/', function(req, res){
res.send('Default route');
});
function getCo(){
return connection.coSql['test'].pool;
}
router.get('/count', function(req, res){
var pool = getCo();
var countQuery = "SELECT COUNT(data) FROM table WHERE data IS NOT NULL";
try {
pool.getConnection(function(errco, connection){
if(errco) return res.send(errco);
connection.query(countQuery, function(error, result){
if (error) throw error;
else {
try{
connection.release();
return res.send(result);
} catch (err) {
return res.send(err);
}
}
});
})
}catch (err){
return res.send(err);
}
})
module.exports = router;
connection_management.js
const fs = require('fs');
var mysql = require('mysql');
var config = fs.readFileSync('config.json');
config = JSON.parse(config);
const coSql = [];
exports.connectionsSql = (req, res, next) => {
for (let i = 0; i < config.sql.databases.length; i++) {
if (coSql[config.sql.databases[i].name]) {
next();
} else {
coSql[config.sql.databases[i].name] = {};
coSql[config.sql.databases[i].name].pool = mysql.createPool({
host: config.sql.databases[i].host,
user: config.sql.user,
password: config.sql.password,
database: config.sql.databases[i].name});
}
}
next();
}
module.exports.coSql = coSql;
config.js
{
"sql":{
"user": "foo",
"password": "bar",
"databases":[
{
"name": "test",
"host": "localhost"
}
]
}
}
Thanks for your help, fixing and understanding the problem.
In route/index.js:
router.get('/count', function(req, res){
var pool = getCo();
var countQuery = "SELECT COUNT(data) FROM table WHERE data IS NOT NULL";
try {
pool.getConnection(function(errco, connection){
if(errco) throw New Error(errco); // <---- CHANGED THIS.
connection.query(countQuery, function(error, result){
if (error) throw error;
else {
try{
connection.release();
return res.send(result);
} catch (err) {
throw New Error(err); // <---- CHANGED THIS.
}
}
});
})
}catch (err){
return res.send(err);
}
})
You might be calling res.send more than once in your code due to the way you've written you error catching.
I have replaced 2 of your res.send() method calls with thrown errors so that they are caught and dealt with in the final catch block at the bottom.
Related
problem: i keep getting the error in title when trying to register a new user only when using postman no idea why.
Also, Proxy problems: Could not proxy request /api/auth/register?hello&world from localhost:3000 to http://localhost:8080/.
Things i've tried to solve proxy was
adding "secure": false in package json.
my auth.js file:
exports.postRegister = async (req, res, next) => {
// User object
const newUser = {
username: req.body.username,
password: req.body.password,
};
// Check if user exists
try {
const user = await User.findOne({ username: newUser.username });
if (user) {
const error = new Error("Username already taken.");
error.statusCode = 422;
return next(error);
}
} catch (error) {
error.statusCode = error.statusCode || 500;
next(error);
}
// creating a hash from the given password
bcrypt.genSalt(12, (err, salt) => {
if (err) {
return next(err);
}
bcrypt.hash(newUser.password, salt, null, async (err, hash) => {
if (err) {
return next(err);
}
try {
// set hashed password as the password field in newUser object.
newUser.password = hash;
// Save newUser
const createdUser = new User(newUser);
await createdUser.save();
// Create jwt token and send
const token = await genToken(createdUser._id, createdUser.username);
res.status(201).json({
success: true,
token,
});
} catch (err) {
err.statusCode = err.statusCode || 500;
next(err);
}
});
});
};
Server.js file:
const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require("body-parser");
const helmet = require("helmet");
const cors = require("cors");
require("dotenv").config();
const mailRoutes = require("./routes/mail");
const authRoutes = require("./routes/auth");
const app = express();
app.use(bodyParser.json());
app.use(helmet());
app.use(cors());
// Routes
app.use("/api/mail", mailRoutes);
app.use("/api/auth", authRoutes);
app.use((error, req, res, next) => {
console.log(error.message);
res.status(error.statusCode).json({
error: true,
messages: [error.message],
});
});
mongoose.connect(process.env.DB_URI, (err) => {
if (err) {
console.log(err);
} else {
console.log("DB Connected");
}
});
const PORT = process.env.PORT || 5000;
app.listen(PORT, () => {
console.log(`Server has started at ${PORT}`);
});
Ok so to anyone who is facing the same problem - i figured it out.
changing from arrow functions to regular function.
apparently bcrypt doesnt accept arrow functions
so instead of:
bcrypt.hash(newUser.password, salt, async => (err, hash){}...
do this:
bcrypt.hash(newUser.password, salt, async function (err, hash){}...
I'm fairly new to Node.js and I am having some issues.
im working on app for learning purposes but i came across this problem
Error: Can't render headers after they are sent to the client.
i didnt know how to make it work
C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\mysql\lib\protocol\Parser.js:437
throw err; // Rethrow non-MySQL errors
^
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at ServerResponse.setHeader (_http_outgoing.js:470:11)
at ServerResponse.header (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\express\lib\response.js:771:10)
at ServerResponse.send (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\express\lib\response.js:170:12)
at ServerResponse.json (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\express\lib\response.js:267:15)
at C:\Users\GameDev\Desktop\Portfolio\reciepe\routes\route.js:32:20
at Query. (C:\Users\GameDev\Desktop\Portfolio\reciepe\models\orm.js:9:9)
at Query. (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\mysql\lib\Connection.js:525:10)
at Query._callback (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\mysql\lib\Connection.js:491:16)
at Query.Sequence.end (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\mysql\lib\protocol\sequences\Sequence.js:83:24)
at Query.ErrorPacket (C:\Users\GameDev\Desktop\Portfolio\reciepe\node_modules\mysql\lib\protocol\sequences\Query.js:90:8)
SQL error :
code: 'ER_PARSE_ERROR',
errno: 1064,
sqlMessage:
'You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near \'NULL,
\'dqdd\'\' at line 1',
sqlState: '42000',
index: 0,
sql:
'INSERT INTO authentication(username,password) VALUES NULL, \'dqdd\'' }
here is the database
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "",
database:'reciepeapp'
});
module.exports = con
the ORM
const con = require('./db')
const orm = {
insertOne: function (values, cb) {
const sqlQuery = "INSERT INTO authentication(username,password) VALUES ?";
con.query(sqlQuery, [values],function (err, data) {
if (err) {
console.log(err)
cb(err, null);
} else {
cb(null, data);
}
});
},
}
module.exports = orm;
here is the route.js
const express = require('express');
const app = express()
const router = express.Router()
const bcrypt = require('bcrypt');
bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
const orm = require('../models/orm')
router.get('/',(req,res)=>
res.render('home')
)
router.get('/login',(req,res)=>
res.render('login')
)
router.get('/register',(req,res)=>
res.render('register')
)
router.post("/register", function (req, res) {
values = [
username = req.body.username,
password = req.body.password
];
orm.insertOne(values, function(error) {
if (error) {
return res.status(401).json({
message: 'Not able to add'
});
}
return res.json({
username: values.username,
password:values.password
});
});
});
module.exports = router
index.js
const express = require('express');
const app = express()
const bodyParser = require("body-parser");
const indexRouter = require('./routes/route')
const con = require('./models/db')
con.connect(function(err) {
if (err) {
return console.error('error: ' + err.message);
}
console.log('Connected to the MySQL server.');
});
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
var exphbs = require('express-handlebars');
console.log(__dirname)
app.use('/',express.static(__dirname + '/public'));
app.engine('handlebars', exphbs());
app.set('view engine', 'handlebars');
app.use('/',indexRouter)
const PORT = 5000;
app.listen(PORT,()=>console.log('it started on 5000'))
May I know what is wrong with my code?
The problem is in your orm file. There the callback is getting called twice(in case err is true/has a value), which in-turn calls the res.json twice. Try changing the below
con.query(sqlQuery, [values],function (err, data) {
if (err) {
cb(err, null);
} else {
cb(null, data);
}
});
I am trying to view the first row of a table but I get the error
TypeError: pendingItem.callback is not a function
at client.connect
var express = require("express");
const {Pool} = require("pg");
var app = express();
var conStr = "postgres://postgres:password#localhost:5432/postgres";
const pool = new Pool();
app.get("/", function(req, res, next) {
pool.connect(conStr, function(err, client, done) {
if (err) {
console.log("not able to get connection " + err);
res.status(400).send(err);
}
client.query("SELECT * FROM Users where id= $1", [1], function(err, result) {
done();
if (err) {
console.log(err);
res.status(400).send(err);
}
res.status(200).send(result.rows);
});
});
});
On Postgres connection Pool using connectionString
First if you are choosing to connect to Postgres using connectionURI, you need to initialize Pool with connectionString param:
const pool = new Pool({
connectionString: connectionString,
})
Then when calling pool.connect you only need to pass callback function:
pool.connect((err, client, release) => {...});
Check documentation on Pooling and different ways of making a connection to Postgres using node-postgres package: here and here
In your case this, it should look like this:
var express = require("express");
const pg = require("pg");
const {Pool} = require("pg");
var app = express();
var conStr = "postgres://postgres:password#localhost:5432/postgres";
const pool = new Pool({
connectionString: conStr
});
app.get("/", function(req, res, next) {
pool.connect(function(err, client, done) {
if (err) {
console.log("not able to get connection " + err);
res.status(400).send(err);
}
client.query("SELECT * FROM Users where id= $1", [1], function(err, result) {
done();
if (err) {
console.log(err);
res.status(400).send(err);
}
res.status(200).send(result.rows);
});
});
});
I'm trying to get a result from MongoDB database return as a response for my GET Request when I make the call I'm getting undefined in the response, I'm able to see the result in console log on the database side of the code. I'm feeling like it might have something to do with it being an array
MongoClient = require('mongodb'),
mongodburl = "mongodb://localhost:27017",
mongo = require('mongodb'),
assert = require('assert');
let method={}
method.insertdata=function(data,collectionpara) {
MongoClient.connect(mongodburl, function (err, db) {
assert.equal(null, err);
let dbo = db.db("hor-usData");
let myobj = data;
dbo.collection(collectionpara).insert(myobj, function (err, result) {
assert.equal(null, err);
console.log("insert data");
db.close();
})
})
}
method.deleteRecords=function(collectionpara) {
MongoClient.connect(mongodburl, function (err, db) {
assert.equal(null, err);
let dbo = db.db("hor-usData");
var myquery = {
title: /^B/
};
dbo.collection(collectionpara).deleteMany(myquery, function (err, obj) {
if (err) throw err;
console.log(obj.result.n + " document(s) deleted");
db.close();
})
})
}
method.getdata=function(collectionpara){
MongoClient.connect(mongodburl, function(err, db) {
if (err) throw err;
let dbo = db.db("hor-usData");
dbo.collection(collectionpara).find().toArray(function(err, result) {
if (err){
return reject(err)
}
console.log('result',result);
return resolve(result);
});
});
}
module.exports = method;
and my router code
let assert = require('assert'),
express = require('express'),
router = express(),
swaggerUi = require('swagger-ui-express'),
database=require('../databaseCon'),
// swaggerDocument = require('./swagger.json'),
utils = require('../utils/utils');
var port = process.env.PORT || 3000;
//get donedeal
router.get('/getDonedeal', function (req, res, next) {
let donedealResult = []
donedealResult=database.getdata('donedeal');
res.send(donedealResult);
});
//get carzone
router.get('/getCarzone', function (req, res, next) {
let carzoneResult = [];
carzoneResult=database.getdata('carzone');
res.send(console.log(carzoneResult));
});
router.get('/cars', function (req, res, next) {
res.router('Mainrouter')
});
router.get('/getCarzone', function (req, res, next) {
var resultArray = []
});
router.listen(port);
//app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));
//app.use('/api/v1', router);
module.exports = router;
It would be great if anyone can help me out. I am new to node.js, and I am trying to send the data into MSSQL database for my initial project, and as per project requirement I was not able to use any other DB other than MSSQL, and I am getting error value into DB while I execute the insert query. I tried to figure out the error more than a day but end up with nothing. Could anyone help me to fix this error.?
Thanks in advance.
// Server.js
var express = require('express');
var app = express();
var port = process.env.port || 3000;
var bodyParser = require('body-parser');
// create application/x-www-form-urlencoded parser
app.use(bodyParser.urlencoded({ extended: true }));
// create application/json parser
app.use(bodyParser.json());
var ProductController = require('./Controller/ProductController')();
app.use("/app/Data", ProductController)
app.listen(port, function () {
var datetime = new Date();
var message = "Server runnning on Port:- " + port + "Started at :- " + datetime;
console.log(message);
});
// App.js
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 ArduinoSensor";
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 Receive Data");
});
})
.catch(function (err) {
conn.close();
res.status(400).send("Error");
});
});
router.route('/')
.post(function (req, res) {
conn.connect().then(function () {
var transaction = new sql.Transaction(conn);
transaction.begin().then(function () {
var request = new sql.Request(transaction);
request.input("start_time", sql.VarChar(50), req.body.start_time)
request.input("end_time", sql.VarChar(50), req.body.end_time)
request.input("length_time", sql.VarChar(50), req.body.length_time)
request.execute("Usp_InsertSensor").then(function () {
transaction.commit().then(function (recordSet) {
conn.close();
res.status(200).send(req.body);
}).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");
});
}).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;
PS:- I have attached the outcome of the coding
Outcome of the image