Update data of MYSQL table by using Node.js

In this article, we are going to learn how to update a record of MYSQL table using Node.js server?
Submitted by Manu Jemini, on November 24, 2017

Prerequisite:

Now, in this article, the very first thing we are going to do is to prepare a server file of node.js where we require the MySQL module to work with MySQL and after that, we prepare a connection by using mysql.createConnection() method of MySQL module.

There are certain things that we have to define inside our create connection methods like host, user, password, and database name.

Now that we are all set to go with our connection, all we need to create a SQL query to update data basically an update query with a field and after that we can use query() method to execute query statement with a callback function in which we can throw error if any and print the message where we can show the number of affected rows.

Note: For updating the record we need at least one field of that record.

Database details:

Hostname: localhost
Port number: 3306
Username: root
Password: 123
Database: demo
Table name: clients
Field: address

Server File

//step-1
var mysql = require('mysql');

//step-2
var con = mysql.createConnection({
  host: "127.0.0.1",
  user: "root",
  password: "123",
  database: "demo"
});

//step-3
con.connect(function(err) {
  if (err) throw err;
  var sql = "UPDATE first SET address = 'Bhopal' WHERE address = 'Delhi'";

//step-4
  con.query(sql, function (err, result) {
    if (err) throw err;
    console.log(result.affectedRows + " record(s) updated");
  });
});

Discussing steps that we have followed in our server file:

Require MySQL module.
Create Connection variable using mysql.createConnection() method.
Connect by using con.connect() method.
Creating an update SQL query.
Execute query by using .query() method.
Shows affected records.

Output/result