Develop Reference

AxiosError: Request failed with status code 404 shows when trying to get data from MongoDB database

I am trying to use the Get method from the code below. I can use the Post method to post new instances to the database but my Get method is not working. When I tried to use the Get method I encountered the "AxiosError: Request failed with status code 404" error.
This is my code that contains the Get and Post methods:
const express = require('express');
const mongoose = require('mongoose');
const { ObjectId } = require('mongodb');
const { connectToDb, getDb, URI } = require('./db');
const Root = require('../models/Root');
const port = process.env.PORT || 7000;
const URL = 'http://localhost:7000'
const axios = require('axios');
// init & middleware
const app = express();
const router = express.Router();
app.use(express.json());
mongoose.set('strictQuery', false);
mongoose.set('bufferCommands', false);
let db
connectToDb((err) => {
if (!err) {
app.listen(port, () => {
console.log(`Listening on port ${port}`);
});
}
});
mongoose.connect(URI, {
useNewUrlParser: true,
useUnifiedTopology: true,
});
// POST
app.post('/roots', async (req, res) => {
const { root_id, node_id, name } = req.body;
if (!root_id || !node_id || !name) {
return res
.status(400).send({ error: 'Please provide all required fields' });
}
const root = new Root({ root_id, node_id, name });
try {
const savedRoot = await root.save();
res.send(root);
} catch (err) {
//console.error('Error saving root:', err);
res.status(400).send(err);
}
});
// GET
app.get('/roots/:root_id', async (req, res) => {
try {
const response = await axios.get(
`${URL}/roots?filter={"where":{"root_id":${req.params.root_id}}}`
);
res.status(200).json(response.data);
} catch (err) {
console.error('Error getting root:', err);
res.status(400).send(err);
// res.status(500).json({ error: 'Could not fetch the root' });
}
});
// DELETE
app.delete('/roots/:root_id', async (req, res) => {
try {
await axios.delete(`${URL}/roots/${req.params.root_id}`);
res.status(200).json({ message: 'Root deleted successfully' });
} catch (err) {
console.error('Error getting root:', err);
res.status(400).send(err);
// res.status(500).json({ error: 'Could not delete the root' });
}
// Call to a method to delete all children nodes of the tree in the Node tables
});
// PATCH
app.patch('/roots/:root_id', async (req, res) => {
try {
const response = await axios.patch(
`${URL}/roots/${req.params.root_id}`,
req.body
);
res.status(200).json(response.data);
} catch (err) {
res.status(500).json({ error: 'Could not update the root' });
}
});
I use this code to connect to the database:
// Use this file to connect to database - easy to switch between local and cloud for testing
const{MongoClient} = require('mongodb')
let dbConnection
// Connect to local database
let URI = 'mongodb://127.0.0.1:27017/PM_AI'
module.exports = {
connectToDb: (cb) => {
MongoClient.connect(URI)
// MongoClient.connect(cloudURI)
.then((client) => {
dbConnection = client.db()
return cb()
})
.catch(err => {
console.log(err)
return cb(err)
})
},
getDb: () => dbConnection,
URI
}
ERROR LOG for the error that I encounter:
{
"message": "Request failed with status code 404",
"name": "AxiosError",
"stack": "AxiosError: Request failed with status code 404\n at settle (D:\\CSDS_395_Project\\AI-PM\\node_modules\\axios\\dist\\node\\axios.cjs:1900:12)\n at IncomingMessage.handleStreamEnd (D:\\CSDS_395_Project\\AI-PM\\node_modules\\axios\\dist\\node\\axios.cjs:2944:11)\n at IncomingMessage.emit (node:events:525:35)\n at endReadableNT (node:internal/streams/readable:1359:12)\n at process.processTicksAndRejections (node:internal/process/task_queues:82:21)",
"config": {
"transitional": {
"silentJSONParsing": true,
"forcedJSONParsing": true,
"clarifyTimeoutError": false
},
"adapter": [
"xhr",
"http"
],
"transformRequest": [
null
],
"transformResponse": [
null
],
"timeout": 0,
"xsrfCookieName": "XSRF-TOKEN",
"xsrfHeaderName": "X-XSRF-TOKEN",
"maxContentLength": -1,
"maxBodyLength": -1,
"env": {},
"headers": {
"Accept": "application/json, text/plain, */*",
"User-Agent": "axios/1.3.3",
"Accept-Encoding": "gzip, compress, deflate, br"
},
"method": "get",
"url": "http://localhost:7000/roots?filter={\"where\":{\"root_id\":1}}"
},
"code": "ERR_BAD_REQUEST",
"status": 404
}
The URL that I use to test my method in Postman is http://localhost:7000/roots/1.
Please let me know what am I doing wrong with my code here.
Thank you very much!

In your expressjs server file, the url you are using in mongoose.connect() refers to the expressjs server itself instead of localhost mongodb instance
So in your server.js/app.js or whatever is your main expressjs server file,
const MONGO_URL = 'mongodb://127.0.0.1:27017/PM_AI'
I can also see that you are using both mongo client and mongoose which I don't understand why... You only need one of these libaries to connect to mongodb from your backend
Also your code is pretty messed up so I've made the following changes
No need to use mongoose strict query and other configurations, simply using mongoose.connect() in latest mongoose version is enough. As mongodb connection establishes, you can launch your server
In terminal, write npm install dotenv. It is a package that is used to access variables in .env file, without it your server won't work properly
I've removed mongo client as it is not needed, simply using mongoose is enough
I don't know why you are making axios requests to your own server. This axios thing is what is causing 404 error. You should use axios only when you need to make api calls from frontend, or make api calls from your backend to some other backend server. For your own server, you should always prefer using a controller function for every route otherwise you will get 404 error. By controller function, I mean instead of axios.get, you need to execute mongoModel.delete() instead of axios.delete() or return mongoModel.findById() instead of axios.get()
For mongodb connection, use MONGO_URL and for connecting your own server, use URL
So the final version of your code should look like:
const express = require('express');
const mongoose = require('mongoose');
const { ObjectId } = require('mongodb');
const Root = require('../models/Root');
const MONGO_URL = 'mongodb://127.0.0.1:27017/PM_AI'
const axios = require('axios');
// For environmental variables in .env file
const dotenv = require("dotenv")
dotenv.config()
// init & middleware
const app = express();
const router = express.Router();
app.use(express.json());
const port = process.env.PORT || 7000
const URL = `http://localhost:${port}`
mongoose.connect(MONGO_URL).then(() => {
console.log("Mongodb connected")
app.listen(port,() =>
{console.log("Server started") }
});
// POST
app.post('/roots', async (req, res) => {
const { root_id, node_id, name } = req.body;
if (!root_id || !node_id || !name) {
return res
.status(400).send({ error: 'Please provide all required fields' });
}
const root = new Root({ root_id, node_id, name });
try {
const savedRoot = await root.save();
res.send(root);
} catch (err) {
//console.error('Error saving root:', err);
res.status(400).send(err);
}
});
// GET
app.get('/roots/:root_id', async (req, res) => {
try {
const response = await axios.get(
`${URL}/roots?filter={"where":{"root_id":${req.params.root_id}}}`
);
res.status(200).json(response.data);
} catch (err) {
console.error('Error getting root:', err);
res.status(400).send(err);
// res.status(500).json({ error: 'Could not fetch the root' });
}
});
// DELETE
app.delete('/roots/:root_id', async (req, res) => {
try {
await axios.delete(`${URL}/roots/${req.params.root_id}`);
res.status(200).json({ message: 'Root deleted successfully' });
} catch (err) {
console.error('Error getting root:', err);
res.status(400).send(err);
// res.status(500).json({ error: 'Could not delete the root' });
}
// Call to a method to delete all children nodes of the tree in the Node tables
});
// PATCH
app.patch('/roots/:root_id', async (req, res) => {
try {
const response = await axios.patch(
`${URL}/roots/${req.params.root_id}`,
req.body
);
res.status(200).json(response.data);
} catch (err) {
res.status(500).json({ error: 'Could not update the root' });
}
});

Data not getting inserted into database, despite of 201 request status - postgresql express js

I am using Typescript, Express, PostgresDB.
Here is my code for connecting to the database cluster.
import { Pool } from "pg";
const myPool = new Pool({
host: `${process.env.DATABASE_URL}`, //somedb.abc.us-east-1.rds.amazonaws.com
database: `${process.env.DATABASE_NAME}`, //dbName
user: `${process.env.DATABASE_USER}`, //dbUser
password: `${process.env.DATABASE_PASSWORD}`, //dbPassword
port: 5432
});
myPool.connect();
Here is my post route:
const router = express.Router();
router.post("/item/new", async (request, response) =>{
try{
const { itemTitle } = request.body;
const myItem = await myPool.query(`INSERT INTO items VALUES('${itemTitle}')`), (resp, err) =>{
if(err){
return err;
}
return resp;
});
return response.status(201).json({message: myItem});
}catch(err){
return response.status(400).json({message: `${err}`});
}
});
When I send the request, I get the following response with a 201 status code, but nothing
is inserted into the database:
{
"message": {}
}

It's because you're sending the callback function with the wrong argument's order. The first argument for the callback is error, not result.
It should be like this:
client.query('SELECT NOW() as now', (error, result) => {
if (error) {
console.log(error.stack)
} else {
console.log(result.rows[0])
}
})
documentation.

You can try to print the query that you are passing to find the error.
The reason is that you are concatenating a json object with string which is wrong, instead try this:
`INSERT INTO items(col1, col2) VALUES(${itemTitle.col1}, ${itemTitle.col2})`

Release PostgeSQL connection Pool in Nodejs

I am trying to connect my application to the database using the connection pool method, its connecting fine, and data insertion is happening fine without any issues but other queries in the same file are slowing down.
I have tried with release() method also not working properly.
How can release the pool to the next query once it's executed the current query?
Below is my dbpool.js file code where I am writing a common generalized database connection,
var pg = require('pg');
var PGUSER = 'postgres';
var PGDATABASE = 'test_database';
var config = {
user: PGUSER, // name of the user account
host: 'localhost',
database: PGDATABASE, // name of the database
password: 'password#AWS',
port: 5432,
max: 10,
idleTimeoutMillis: 10000
};
const pool = new pg.Pool(config);
const DB = {
query: function(query, callback) {
pool.connect((err, client, done) => {
if(err){ return callback(err); }
client.query(query, (err, results) => {
// done();
client.release();
// if(err) { console.error("ERROR: ", err) }
if(err) { return callback(err); }
callback(null, results.rows);
})
});
}
};
module.exports = DB;
I tried with both the done() and client.release() method but no luck. If I use both then I am getting an error message client is already released.
Below is my socket.js file code:
var express = require('express');
const connection = require('./dbpool.js');
if(arData == '0022'){
const queryText = "INSERT INTO alert(alert_data) VALUES('"+arData+"')";
connection.query(queryText,(err, res) => {
if(err){
console.log(err.stack);
}
});
}
if(arData == '0011'){
const queryText = "INSERT INTO table2(alert_data) VALUES('"+arData+"')";
connection.query(queryText,(err, res) => {
if(err){
console.log(err.stack);
}
});
}
function ReverseCommunication(){
const select1 = "SELECT * FROM alert WHERE action = '0' ORDER BY alert_id ASC LIMIT 1";
connection.query(select1, (err, res) =>{
if(err) {
console.log("Error1");
res.json({"error":true});
}
else{
console.log("res==",res);
}
});
}
setInterval(function(){
ReverseCommunication();
}, 2000)

With pool you shouldn't need to close the connection. With pool it will reuse the connection pool for subsequent request so you don't have to connect to the DB each time.
(i'm not a PG expert here, sure other could expand on that way better then I )
What works for us is to set up the dbpool file you have like this
const {Pool,Client} = require('pg');
const pool = new Pool({
user: process.env.POSTGRES_USER,
host: process.env.POSTGRES_URL,
database: process.env.POSTGRES_DATABASE,
password: process.env.POSTGRES_PASSWORD,
port: process.env.POSTGRES_PORT,
keepAlive: true,
connectionTimeoutMillis: 10000, // 10 seconds
max: 10
});
pool.connect()
.then(() => console.log('pg connected'))
.catch(err => console.error(err))
module.exports = pool
Then use the pool.query like you have now with pool.connect
Also, just a side note what lib are you using for PG? Noticed your queries are dynamic, you may want to adjust those to prevent possible SQL-injection.

How to improve node js code for production and split it properly across files?

I'm new to javascript and node.js.
Can someone answer the following questions.
1. How I split the PostgreSQL part properly in an other file.
2. How I the pest practice is to use the pg pools.
3. How I improve this code for production.
const express = require('express');
const app = express();
const pg = require('pg');
const pool = new pg.Pool({
user: 'admin',
password: 'test123!',
host: '127.0.0.1',
port: '5432',
database: 'test_db'
});
app.get('/api/recipes', function(req, res){
pool.connect(function(err, client, done) {
if(err){
console.log('Connection failed '+ err);
res.status(400).send(err);
}
client.query('SELECT * FROM recipes;', function(err, result) {
done();
if(err){
console.log('Error with query! ERROR code: ' + err.code);
res.status(400).send(err);
}
else{
res.status(200).send(result.rows)
}
});
});
});
app.get('/api/recipes/:id', function(req, res){
var id = req.params.id;
pool.connect(function(err, client, done) {
if(err){
console.log('Connection failed ' + err);
res.status(400).send(err);
}
else{
client.query('SELECT * FROM recipes WHERE recipes_id = $1;', [id], function(err, result) {
done();
if(err){
console.log('Error with query! ERROR code: ' + err.code);
res.status(400).send(err);
}
else{
res.status(200).send(result.rows)
}
});
}
});
});
app.listen(3000,function(){
console.log('Server listen on port 3000');
});

There are a lot of ways folks go to split the code you've described. I'll take it piece by piece.
First, pull any configurable variables out and setup one file that can get them from the environment (possibly with dev defaults in place, your choice on that). You can use a library like commander or convict, but honestly I prefer to just write a simple file that pulls them myself:
// ./config.js
module.exports = {
pool: {
user: process.env.DB_USER || 'admin',
password: process.env.DB_PW || 'test123!',
host: process.env.DB_HOST || '127.0.0.1',
port: process.env.DB_PORT || '5432',
database: process.env.DB_NAME || 'test_db'
}
};
As for your database calls, some folks like to use ORM-like stuff such as sequelize, but again I tend to start simple and add things as needed. In your case, you should think about what boilerplate stuff you can make common code around, and then wrap those into simple modules that only expose to the calling code stuff it really needs. For example, you will note that most of your routes are going to connect to the pool, test for an error, then run a query if it doesn't error out, and finally render either the error or query results, right? So that can all be wrapped into a fairly simple query function that handles the boilerplate internally and works with just a query expression and a callback, for example:
// ./db/index.js
const pg = require('pg');
const config = require('./config');
const pool = new pg.Pool(config.pool);
function query(sql, params, callback) {
// maybe check for valid inputs here or something, but at least normalize in case folks don't pass params
if(arguments.length < 3) {
callback = params;
params = null;
}
pool.connect((err, client, done) => {
// just exit here and let the calling code know there was a problem
if(err) return callback(err);
// I haven't tested this w/ the pg library recently, you might have to do two of these if it doesn't like null as a second argument
client.query(sql, params, (err, result) => {
if(err) return callback(err);
done();
// calling code probably doesn't care about anything but rows, but you can do other stuff here if you prefer
return callback(null, result.rows);
});
});
};
// You can also add additional functions if you want shorthand for doing things like query by ID or with params, or similar
module.exports = { query };
I also think that it can be helpful to store the SQL strings somewhere centrally, or on model objects, just to make the routing code note have to care about that. For a super simple example using your two routes, I might do something like this:
// ./db/queries.js
module.exports = {
RECIPES: {
LIST: 'SELECT * FROM recipes;',
FIND_BY_ID: 'SELECT * FROM recipes WHERE recipes_id = $1;'
}
};
Ok, so now your routing code can be quite simple, you can just get the db module and work the query, letting the routing worry just about what it's got to do with the request and response. Another option that folks like is to actually create a module for each model in your app (e.g. a Recipe) that wraps the above two files into a set of static functions so that your routes don't even know they're querying specifically. The calls in that case would be something like Recipe.list(cb) or Recipe.findById(id, cb). This is a style made popular by Ruby on Rails a few years ago, it has mixed acceptance in the Node community, but I'm mentioning it for completeness.
// ./routes/recipes.js
const router = require('express').Router();
const db = require('./db');
const queries = require('./db/queries');
router.get('/api/recipes', (req, res, next) => {
db.query(queries.RECIPES.LIST, (err, rows) => {
if(err) return next(err);
return res.send(rows); // status 200 is the default here
});
});
router.get('/api/recipes/:id', (req, res, next) => {
const id = req.params.id;
db.query(queries.RECIPES.FIND_BY_ID, [id], (err, rows) => {
if (err) return next(err);
return res.send(rows);
});
});
Finally, in your main Express setup file:
// ./app.js
const express = require('express');
const app = express();
const recipeRoutes = require('./routes/recipes') // note if you have an index.js file that gets imported just by calling for the folder, so that's a way to group features as well
app.use(recipeRoutes);
// I'm a big fan of error handling middleware. There's a more complex approach I did in [praeter][4] that gives you http-verb based errors that you can then catch and send the appropriate status, but that's again more complex than you might need here.
app.use((err, req, res, next) => {
// this can be as simple or as complex as you like.
// note it's a best practice to send only "clean" messages to the client, so you don't give away that you're using a Postgres db or other stuff that makes hacking easier.
console.error(err);
res.status(500).send('Oops! Something went wrong!!');
});
Obviously, there's a lot of ways to skin this cat, so I'd recommend mostly just looking for where you're repeating yourself, and then refactor to repeat less. Also, if you're interested in making more production-ready apps in general, the 12 factor app is a must-read.

To answer number 1,
dbPool.js
const pg = require('pg');
export.pool = new pg.Pool({
user: 'admin',
password: 'test123!',
host: '127.0.0.1',
port: '5432',
database: 'test_db'
});
app.js
const express = require('express');
const app = express();
const pool = require('./dbPool');
....

You should create config file and require that file in app.js
--config
----config.js
--app.js
var config = {
production: {
pool: {
user: 'admin',
password: 'test123!',
host: '127.0.0.1',
port: '5432',
database: 'test_db'
}
},
development: {
pool: {
user: 'admin',
password: 'test123!',
host: '127.0.0.1',
port: '5432',
database: 'test_db'
}
}
}
exports.get = function get(env) {
return config[env] || config.development;
}

Node.js MySQL connection not being released properly

I think my connections aren't being released properly. Sometimes I get an error stating that my pool has reached its limit. Also, sometimes accessing the db randomly takes 15+ seconds. Whenever I check how many connections are in use using pool._allConnections.length, it never returns anything above 60. Here is my code:
const mysql = require('mysql');
const config = require('./config.json');
const pool = mysql.createPool({
connectionLimit : 999,
host: config.host,
user: config.user,
password: config.password,
database: config.database
});
const db = (() => {
_query = (query, params, callback) => {
pool.getConnection((err, connection) => {
if (err) {
callback(null, err);
} else {
connection.query(query, params, (err, rows) => {
connection.release();
if (!err) {
callback(rows);
} else {
callback(null, err);
}
});
}
});
};
return {
query: _query
};
})();
module.exports = db;

i've faced same issue and https://github.com/mysqljs/mysql/issues/1518 help me. Notice line
Yeah, that was the issue. I was calling mysql.createPool on each
query.
Actually you are importing db from query.js (let say your post code) to fire a query. every time you fire a query it create a new pool.to solve this issue you can put createPool code block to app.js and can share it global or can use in query.js via any other code style.
Referring official doc https://github.com/mysqljs/mysql#pooling-connections find line
Since the pool.query method is a short-hand for the pool.getConnection
-> connection.query -> connection.release() flow, calling pool.end() before all the queries added via pool.query have completed,
later i used this to stop headache of release connection