mysql2/promise require database connection file

Question

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?

Answer 1

If you use aconnection 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();