Order Classs

order.php

<?php 

class Order {

	public $_order;

	public function __construct( $order_id ) {

		if ( empty( $order_id ) ) {
			throw new Exception( '$order_id empty' );
		}

		$this->_order = $this->get( $order_id );

	}

	function get( $order_id ) {

		global $wpdb;

		$table_name = $wpdb->base_prefix . 'orders';

		$orders = $wpdb->get_row( "SELECT * FROM $table_name WHERE order_id = " . $order_id, ARRAY_A );

		return $order;

	}

	function get_total() {

		return $this->_order['total'];

	}

}