I have only been working with PHP before going to Node.JS. What I was able to do in PHP when working with MYSQL was that I could include the database.php file in the files I wanted to execure queries in.
It doesn't seem to be the same in Node.Js. This is my database.js file
const mysql = require("mysql2/promise");
const db = mysql.createConnection({
host: 'localhost',
user: 'root',
password: 'XXXX',
database: 'nodelogin'
});
module.exports = db;
Then I require this in my file login.js
const db = require("../../database");
However, when I then try to run db.query(sql, [variable]) I get db.query is not a function.
Why is this? It shouldn't be that more complicated or should it?
If you use a connection pool instead, you can include the pool once, then call query on it, like so:
db-config.js
const mysql = require("mysql2/promise");
console.log("Creating connection pool...")
const pool = mysql.createPool({
host: 'localhost',
user: 'user',
database: 'test_db',
password: 'password'
})
module.exports = pool;
test.js
// Require to whereever db-config is
const pool = require('./db-config.js');
async function testQuery() {
const results = await pool.query("select * from users");
console.table(results[0]);
}
testQuery();
Related
connection.js
var mysql = require("mysql");
const { createPool } = require("mysql");
const pool = createPool({
port: process.env.DB_PORT,
host: process.env.DB_HOST,
user: process.env.DB_USER,
password: process.env.DB_PASS,
database: process.env.MYSQL_DB,
connectionLimit: 10,
});
module.exports = pool;
product.service.js
const pool = require("../../../config/database");
module.exports = {
viewVariate: (callBack) => {
pool.query(
`SELECT varId , varName FROM variations WHERE varIsActive='1'`,
(errors, results, fields) => {
if (errors) {
return callBack(errors);
}
return callBack(null, results);
}
);
},
}
I have to maintain more than 100 users. so each person has own database in that node app. each person database name call via API , so I need to set given database name to above pool dynamically , I referred may ways. it did not work. connection.js file is my database connection with pool. then it call to service files to make connection queries. for that pool data obtains form env file. it doesn't matter when config mentioned requirement will be done.
I am tasked with adding a MySql database to a microservice application for work. I am the only person on this task and don't really have anyone to turn too for advice so I am reaching out to the internets for help. I have succesfully deployed a pod that is running a small test application and the cloud-sql-proxy. I have scoured the documentation trying to figure out how to connect to the db and perform a query and this is what I have come up with (but it doesn't work).
const express = require('express');
const mysql = require('mysql');
const bodyParser = require('body-parser')
const cors = require('cors');
const axios = require('axios');
const app = express();
app.use(bodyParser.json());
app.use(cors())
app.enable('trust proxy');
// Automatically parse request body as form data.
app.use(express.urlencoded({extended: false}));
// This middleware is available in Express v4.16.0 onwards
app.use(express.json());
// [START cloud_sql_mysql_mysql_create_tcp]
const createTcpPool = async config => {
// Extract host and port from socket address
const dbSocketAddr = process.env.DB_HOST.split(':');
// Establish a connection to the database
return mysql.createPool({
user: process.env.DB_USER, // e.g. 'my-db-user'
password: process.env.DB_PASS, // e.g. 'my-db-password'
database: process.env.DB_NAME, // e.g. 'my-database'
host: dbSocketAddr[0], // e.g. '127.0.0.1'
port: dbSocketAddr[1], // e.g. '3306'
// ... Specify additional properties here.
...config,
});
};
// [END cloud_sql_mysql_mysql_create_tcp]
var pool = createTcpPool();
const stuff = pool.query('SELECT * FROM entries');
function getQuery() {
console.log(stuff);
}
getQuery()
Here is a picture of the error I get when I deploy the pod and the logs from the proxy to verify it's running
I'm pretty new to MySql and GKE and trying to figure this out has been a huge struggle. I just want to know how I can actually query the db and would greatly appreciate some assistance or code sample to point me in the right direction, thanks internets.
As mentioned in the thread1 ,
Handling such functions can be done through following example :
const mysql = require('mysql');
const pool = mysql.createPool({ connectionLimit : 1, socketPath: '/cloudsql/' + '$PROJECT_ID:$REGION:$SPANNER_INSTANCE_NAME',
user: '$USER', p
assword: '$PASS',
database: '$DATABASE' });
exports.handler = function handler(req, res)
{ //using pool instead of creating connection with function call
pool.query(`SELECT * FROM table where id = ?`,
req.body.id, function (e, results) {
//made reply here
}); };
For more information you can refer to the documentation related to TCP connection when using Node js.
const createTcpPool = async config => {
// Extract host and port from socket address
const dbSocketAddr = process.env.DB_HOST.split(':');
// Establish a connection to the database
return mysql.createPool({
user: process.env.DB_USER, // e.g. 'my-db-user'
password: process.env.DB_PASS, // e.g. 'my-db-password'
database: process.env.DB_NAME, // e.g. 'my-database'
host: dbSocketAddr[0], // e.g. '127.0.0.1'
port: dbSocketAddr[1], // e.g. '3306'
// ... Specify additional properties here.
...config,
});
};
So trying to create a pool by calling createTcpPool seems to have been the issue. I changed it to
let pool = mysql.createPool({
user: process.env.DB_USER, // e.g. 'my-db-user'
password: process.env.DB_PASS, // e.g. 'my-db-password'
database: process.env.DB_NAME, // e.g. 'my-database'
host: '127.0.0.1', // e.g. '127.0.0.1'
port: '3306'
});
and got a succesful return from my db.
I'm losing my mind on this one. I have my app.js which creates a connection to mysql. It works fine like this :
app.js
const path = require('path')
const hbs = require('hbs')
const express = require('express')
const mysql = require('mysql')
const app = express()
const port = process.env.PORT || 3000
const db = mysql.createConnection({
host: "localhost",
user: "root",
password: "password",
database: "test"
});
db.connect((error) => {
if(error) throw error
console.log("MYSQL Connected")
})
But it doesn't work with this :
app.js
const path = require('path')
const hbs = require('hbs')
const express = require('express')
const dotenv = require('dotenv')
const mysql = require('mysql')
dotenv.config({ path: './.env' })
const app = express()
const port = process.env.PORT || 3000
const db = mysql.createConnection({
host: process.env.HOST,
user: process.env.USER,
password: process.env.PASSWORD,
database: process.env.DATABASE
});
db.connect((error) => {
if(error) throw error
console.log("MYSQL Connected")
})
.env
DATABASE = test
HOST = localhost
USER = root
PASSWORD = password
It recognizes the values I have stored in my .env file since my IDE is showing me the values when I type them in and as long the values of user & password are typed in app.js (but not host and database), it works.
I'm new to MySQL, never used it before, and I'm on Windows. So if I need to do some command lines, can you please specify in which terminal I should type them in ?
Can someone help me ?
Thank you !
Found the answer.
For some reason, this path :
dotenv.config({ path: './.env' })
Didn't work. I had to do it like this :
const path = require('path')
const dotenv = require('dotenv')
dotenv.config({ path: path.join(__dirname, './.env') })
I found this solution by using console.log() on the variables (process.env.HOST, etc...). They were undefined.
Conclusion : always console.log() your stuff.
I am using the mysql2 package for connecting node with MySQL and I am using a .env file to store my username and password. But when I use it in my config for connecting MySql it doesn't load. It throws the following error whenever I hit an endpoint using Postman.
Error: Access denied for user 'undefined'#'localhost' (using password: YES)
Below is my code:
const express = require("express");
const router = express.Router();
const mysql = require("mysql2");
const connection = mysql.createPool({
user: `${process.env.DB_USERNAME}`,
host: "localhost",
password: `${process.env.DB_PASSWORD}`,
waitForConnections: true,
connectionLimit: 10,
queueLimit: 0,
database: "issue",
});
I am using dotenv to load env variables and initialized in my entry file as:
require('dotenv').config();
What am I doing wrong?
As a side effect of the way JavaScript coerces types, process.env.foo will result in "undefined" if it is undefined and used in a string.
There is either a typo in your dotenv config file or else some other problem with your use of dotenv.
I would recommend more defensive coding to give a better error message when this happens. (The following code is untested, but you will no doubt get the idea.)
const express = require("express");
const router = express.Router();
const mysql = require("mysql2");
const dbUsername = process.env.DB_USERNAME;
const dbPassword = process.env.DB_PASSWORD;
if (!dbUsername) {
throw new Error('DB_USERNAME environment variables must be set');
}
if (!dbPassword) {
throw new Error('DB_PASSWORD environment variables must be set');
}
const connection = mysql.createPool({
user: dbUsername,
host: "localhost",
password: dbPassword,
waitForConnections: true,
connectionLimit: 10,
queueLimit: 0,
database: "issue",
});
I'm getting confused. All the tutorials I see with mySql end up with something like this:
in models/dbconnection.js
var mysql = require('mysql');
port = process.env.PORT || 3333;
if (port == 3333) {
var connection = mysql.createConnection({
host: 'localhost',
port: 3306,
user: 'root',
password: 'root',
database: 'nameDataBase',
insecureAuth: true
});
} else {
console.log("Error");
}
connection.connect();
module.exports = connection;
And then in routes/user.js
...
router.delete("/:id", verifyToken, (req, res) => {
const newLocal = "DELETE FROM login_user WHERE id = ?";
connection.query(newLocal, [req.params.id], (err,rows,fields) => {
if (err) {
res.sendStatus(500);
return;
}
console.log(rows.affectedRows);
res.status(200).send({delete: rows});
});
});
module.exports = router;
model and controller aren't getting mixed here? If tomorrow I want to change the type of database, I have to make changes in the model and in the routes. Shouldn't I make functions such as getAllUsersBlaBla(params) in something like models/user.js and then call it from routes/user.js ?
I agree. There shouldn't be any database queries in the router, which is considered part of the controller in MVC.
The model should provide wrapper functions around database queries that can be called from the controller.
A lot of node apps (and probably tutorials) will choose simplicity rather than modularity, that's why you would see code like that.