var mysql = require('mysql');

​

var con = mysql.createConnection({

  host: "localhost",

  user: "myusername",

  password: "mypassword",

  database: "mydb"

});

​

con.connect(function(err) {

  if (err) throw err;

  //Update the address field:

  var sql = "UPDATE customers SET address = 'Canyon 123' WHERE address = 'Valley 345'";

  con.query(sql, function (err, result) {

    if (err) throw err;

    console.log(result.affectedRows + " record(s) updated");

  });

});

​