Connect to Joomla Database from custom PHP file and respond with JSON data

fetchData.php

<?php
define( '_JEXEC', 1 );
define('JPATH_BASE', '../../../');
require_once ( JPATH_BASE .'/includes/defines.php' );
require_once ( JPATH_BASE .'/includes/framework.php' );

$database = &JFactory::getDBO();
$sql = "SELECT * FROM `b7j6z_content` WHERE `state` = '1'"; // Select data from DB
$database->setQuery( $sql );
$result=$database->loadAssocList();

header('Content-type: application/json');
header('Access-Control-Allow-Origin: *'); // CORS Settings
$myJSONString = json_encode($result);
echo $myJSONString;
?>