node js tutorial sql code example

Example 1: how to manage a db connection in javascript

//put these lines in a seperate file
const mysql = require('mysql2');

const connection = mysql.createPool({
    host: "localhost",
    user: "",
    password: "",
    database: ""
    // here you can set connection limits and so on
});

module.exports = connection;

//put these on destination page
const connection = require('../util/connection');

async function getAll() {
    const sql = "SELECT * FROM tableName";
    const [rows] = await connection.promise().query(sql);
    return rows;
} 
exports.getAll = getAll;

Example 2: use nodejs mysql

var mysql      = require('mysql');var connection = mysql.createConnection({  host     : 'localhost',  user     : 'me',  password : 'secret',  database : 'my_db'}); connection.connect(); connection.query('SELECT 1 + 1 AS solution', function (error, results, fields) {  if (error) throw error;  console.log('The solution is: ', results[0].solution);}); connection.end();