I'm attempting to use a variable userEmail (which is assigned the user's email who is currently logged into my app) as a query for my api as I only want to search and return documents from my mongodb that relate to that specific email. I'm struggling to figure out how to pass this variable from my reactjs app to my api and utilising it, I don't even know if it is possible so any help would be great.
I'm using axios to make my GET request.
api.js contains my api helper functions
export async function surveyApiGet () {
let response = await axios.get('http://localhost:6000/'); // dateApi.js
return response.data;
}
dateApi.js is the api surveyApiGet() calls and at the moment my query is just regex that matches any emails, rahter than filtering to just the current user.
let MongoClient = require('mongodb').MongoClient;
var url = "mongodb://127.0.0.1:27017/";
const express = require('express');
const app = express();
app.use(express.json());
app.get('/', function (req, res) {
MongoClient.connect(url, function(err, db) {
if (err) throw err;
var dbo = db.db("manderleydb");
var query = { userId : /^(.)/ };
dbo.collection("manderleySurveyCompleted").find(query).sort({ date: 1}).limit(1)
.toArray(function(err, result) {
if (err) throw err;
console.log(result);
db.close();
res.status(200).json(JSON.stringify(result));
});
});
});
app.listen(6000, () => {
console.log('listening on port 6000');
});
Landing.js is where I make the call to my api helper function
surveyApiGet()
.then(response => {
// code
})
.catch(err => {
err.message;
});
For this, you can do a POST request to your Nodejs API and you can include the user's email with that request. To do so what you have to do is something like the following.
const usersEmail = "example#email.com"
Then through Axios, you can post this code to Nodejs API as follows.
const data = await axios.post("http://localhost:6000/", {
usersEmail : usersEmail
});
After you send this to Nodejs you can hold the value of the user's email through the request's body as follows. Change your endpoint to post instead of get.
app.post("/", function (req, res) {
const userEmail = req.body.userEmail;
//Put your MongoDB query and the status code here.
})
Drop a comment if you have any unclear points.
Related
I'm using an Oracle database, and every time it updates, the server doesn't understand this update and needs me to drop it for it to update the data.
const express = require('express');
const oracledb = require('oracledb');
const app = express();
var cors = require('cors')
app.use (cors())
app.engine('html', require('ejs').renderFile);
app.set('view engine', 'html');
// Connection details for the Oracle database
const connectionString = 'dbprod';
const user = 'sapiensproducao';
const password = 'fabrica';
// Connect to the database
oracledb.getConnection(
{
connectionString: connectionString,
user: user,
password: password
},
function(err, connection) {
if (err) {
console.error(err.message);
return;
}
console.log('Connection was successful!');
// Execute a SQL query
const query = 'SELECT CODEMP,CODORI,NUMORP,SEQEOQ,DATREA,HORREA,CODPRO,CODDER,QTDRE1,QTDRFG,CODLOT,OBSEOQ from USU_VPROEXT ORDER BY DATREA DESC, HORREA DESC';
connection.execute(query, [], (err, result) => {
if (err) {
console.error(err.message);
return;
}
console.log('Query was successful!');
console.log()
// Render the HTML template and pass the query results as a local variable
app.get('/teste', (req, res) => {
res.json(result.rows)
});
});
}
);
app.listen(3000, () => {
console.log('Server is listening on port 3000');
});
I thought of creating a loop for this SELECT function, but how can I create it?
How can I keep running this select in a loop, to keep the data always updated?
In the structure of your web server, you only ever query the database once and then create an endpoint to serve that data. Instead, create an endpoint which queries the data whenever it's invoked. Which may look more like this:
// define the endpoint
app.get('/teste', (req, res) => {
// within the endpoint, query the database
oracledb.getConnection(
{
connectionString: connectionString,
user: user,
password: password
},
function(err, connection) {
if (err) {
console.error(err.message);
// DON'T DO THIS, return an actual response to the user
return;
}
console.log('Connection was successful!');
const query = 'SELECT CODEMP,CODORI,NUMORP,SEQEOQ,DATREA,HORREA,CODPRO,CODDER,QTDRE1,QTDRFG,CODLOT,OBSEOQ from USU_VPROEXT ORDER BY DATREA DESC, HORREA DESC';
connection.execute(query, [], (err, result) => {
if (err) {
console.error(err.message);
// DON'T DO THIS, return an actual response to the user
return;
}
console.log('Query was successful!');
console.log();
// return the results to the user
res.json(result.rows);
});
});
});
The key difference here is that instead of wrapping the endpoint in the query, you wrap the query in the endpoint. So every time the endpoint is invoked it re-queries the database.
Please also note the comments for your error handling. If you just return; from the function and never return a response to the client, the client will just hang until it times out. Return an actual response, which can include error codes, messages, anything you like. Even just res.json(false); would be better than no response at all.
Does anyone know why my request just gets stuck loading when trying to access my database ?
My database name is test. If set the database: books or something like that for example. Then it returns the error database is unknown: books so I assume that my password is correct it just isn't finding the test data base ?
// To import these packages remember to add "type":"module" to package Json
import express from "express";
import mysql from "mysql";
const app = express();
const db = mysql.createConnection({
host: "localhost",
user: "root",
password: "keks000207",
database: "test",
});
// This is an API request with an Express server
app.get("/", (req, res) => {
res.json("Hello this is the backend");
});
app.get("/books", (req, res) => {
const q = "SELECT * FROM books";
db.query(q, (err, data) => {
if (err) return res.json(err);
return data;
});
});
app.listen(8800, () => {
console.log("Connected to backend!");
});
Try db.connect() or similar method available in the file itself.
And Instead of return data inside the callback of db.query, you should use res.send(data), then you will get the response in the GET /books API.
This posts to the DB successfully:
var express = require("express");
//rest of boilerplate
//the below function posts 'subscribingUserEmail' argument to the DB
async function postToDB(subscribingUserEmail) {
await postEmailToDatabase({
email_address: subscribingUserEmail
});
}
postToDB("example#gmail.com");
app.post("/emailList", function(req, res) {
//nothing yet
});
This does not:
var express = require("express");
//rest of boilerplate
//the below function posts 'subscribingUserEmail' argument to the DB
async function postToDB(subscribingUserEmail) {
await postEmailToDatabase({
email_address: subscribingUserEmail
});
}
app.post("/emailList", function(req, res) {
//call the same function but inside the post method instead
postToDB("example#gmail.com");
});
The difference is where I make the async "postToDB" function call. Is there some way to make this function call from within the post method?
Return the result. This will work assuming postEmailToDatabase is setup correctly in your app
async function runSubscribe(subscribingUserEmail) {
const response = await postEmailToDatabase({email_address: subscribingUserEmail});
return response;
}
app.post("/emailList", async function (req, res) {
//get the email from the frontend's post request
subscribingUserEmail = req.body;
//then pass the email into the top defined function
const result = await runSubscribe(subscribingUserEmail);
// or const result = await postEmailToDatabase({...})
res.send(result)
});
If your req.body has multiple parameters you can deconstruct to keep it clean
{ subscribingUserEmail } = req.body
This is assuming you have that parameter on your body object.
If you don't then you'll need to backup and do
console.log(req.body)
i wrote a login page code in js that runs on node express.js server and anyone can put their username /email and password and all that data goes into an json file and it looks like this
{"username":"admin","password":"pasword","email":"user#stackoverflow.com","timestamp":1598668572045,"_id":"dx8HqKkVWe8olH5z"}
i managed to get the timestamp and NeDB gives a random _id to that object.
and when you login you go to a home page that looks like this
but the user gets the username value when there is on object only on the database which is "database.json"
if there is more than 1 object on the database that action will crash and the client can't see his name or any thing it shows nothing .
i don't know how to make it work with several objects on the database.
i thought JSON.parse Or stringfy could make it work but i don't know how to use them on my case.
so here is the js code
var jsonn = '/database.json';
async function userinfo() {
const response = await fetch(jsonn);
const data = await response.json();
var { username, password } = data;
document.getElementById('user').textContent = username;
console.log (data)
console.log (username);
console.log (id);
}
userinfo();
i appreciate any help, if you got any idea please share it with me i really need your help.
UPDATE :
the error message says :
uncaught (in promise) syntaxError : unxpected token in json positon 126.
my server.js code :
const Datastore = require('nedb');
app.listen(2000, () => console.log('listening at 3000'));
app.use(express.static('/public'));
app.use(express.json({
limit: '1mb'
}));
const database = new Datastore('public/database.json');
database.loadDatabase();
app.post('/public', (request, response) => {
const data = request.body;
const timestamp = Date.now();
data.timestamp = timestamp;
database.insert(data);
response.json(data);
console.log(data);
var logdate = new Date;
console.log(logdate);
});
There were some issues with the way that you are calling the DB insert. Basically, on every post request, you allow an insert. This is causing you to have multiple users with the same username. When you search for users by username then you will get a bunch of users. Instead, you want something like the sample code below.
I removed the status public to make it easier to test so make sure to add it back in so you can test front end code. Right now there's just a GET request endpoint so you can get the data by username through a query. This requires more cleanup and checks but at least it will get you started. Also, I remove the password and DB _id from the response as this is probs data you don't want to send back. Ideally, you will encrypt the password before storing it in DB.
const express = require('express');
const app = express();
const Datastore = require('nedb');
app.listen(3000, () => console.log('listening at 3000'));
app.use(express.json({
limit: '1mb'
}));
const database = new Datastore('public/database.json');
database.loadDatabase();
app.get('/public', (req, res) => {
const { username } = req.query;
database.findOne({
username,
}, (err, user) => {
if(err) {
return res.sendStatus(500);
}
delete user._id;
delete user.password;
return res.json(user);
});
});
app.post('/public', (req, res) => {
const data = req.body;
const {
username
} = data;
database.findOne({
username,
}, (err, user) => {
if(err) {
return res.sendStatus(500);
}
if(user) {
delete newUser._id;
delete newUser.password;
return res.json(user)
}
data.timestamp = Date.now();
database.insert(data, (createError, newUser) => {
if(createError) {
return res.sendStatus(500);
}
delete newUser._id;
delete newUser.password;
res.json(newUser);
});
});
});
I have 3 files. db.js, app.js, commentController.js.
I am including my connection in every request in my app so that I wont be repeating the code connection again and again. Is this a bad / unsecure practice? Is there a better/proper way to implement this?
db.js
const mysql = require('mysql');
const pool = mysql.createPool({
host : 'host',
user : 'user',
password : 'password',
database : 'dbname'
});
exports.pool = pool;
app.js
const db = require('./db');
app.use((req, res, next) => {
req.pool = db.pool;
next();
});
commentController.js
exports.showComments = (req, res) => {
req.pool.getConnection((err, conn) => {
conn.query(`SELECT * FROM comments`, (err, results, fields) => {
conn.release();
if (err) throw err;
res.render('comments', { results });
});
});
};
If your only reason for doing this is to avoid duplicating code, then I think it's a bad idea. People looking at your code (or you looking at your code in a year) aren't going to naturally expect a db connection to be a property of req. And you aren't saving yourself any trouble really.
Just require() the database pool in the file and use it.
commentController.js
const db = require('./db');
require() will return the same pool to all your modules.
It's also not clear why you are requesting a connection rather than using the pool (I'm making some assumptions about the lib you're using).
Normally you should be able to do:
const db = require('./db');
exports.showComments = (req, res) => {
db.query(`SELECT * FROM comments`, (error, results, fields) => {
if (err) throw err;
res.render('comments', { results });
});
});
This saves the trouble of requesting and returning connections and just lets the pool do it's work.