Magento export order item data

<?php

class Bysoft_Export_Model_Order extends Mage_Core_Model_Abstract
{
    protected function _construct(){

       $this->_init("export/order");
       $this->_write = Mage::getSingleton('core/resource')->getConnection('core_write');
       

    }
    public function truncate_table() {
    	$sql = 'truncate table bysoft_exportorder';
    	$this->_write->query($sql);
    	
    }
    public function run($start = '', $end = '') {
   
    	$this->truncate_table();
    	
    	//get all complete or  processing or shipped order
    	$order_collection = Mage::getModel('sales/order')->getCollection()
    		->addFieldToFilter('status', array('in'=>array('complete','processing','shipped')));
    	
    	if ($start) {
    		$start_year = substr($start, 0, 4);
    		$start_month = substr($start, 4, 2);
    		$start_date = substr($start, 6, 2);
    		$start_datetime = $start_year . '-' . $start_month . '-' .$start_date . ' 0:0:0';
    		$order_collection->addFieldToFilter('created_at', array('gt'=>$start_datetime));
    	}
    	

    	
    	if ($end) {
    		$end_year = substr($end, 0, 4);
    		$end_month = substr($end, 4, 2);
    		$end_date = substr($start, 6, 2);
    		$end_datetime = $end_year . '-' . $end_month . '-' .$end_date . ' 23:59:59';
    		$order_collection->addFieldToFilter('created_at', array('lt'=>$end_datetime));
    		
    	}
    	
    	$order_collection->setOrder('created_at', 'ASC');
    	
         foreach ($order_collection as $_order) {
         	//get all order itemes
         	$order_increment_id = $_order->getData('increment_id');
         	$purchased_on = $_order->getData('created_at');
         	$ordered_items = $_order->getAllVisibleItems();
         	$shippingId = $_order->getShippingAddress()->getId();
         	$shippingAddress = Mage::getModel('sales/order_address')->load($shippingId);
         	$shipping_to_name = $shippingAddress->getData('firstname') . ' ' . $shippingAddress->getData('lastname');
         	$status = $_order->getData('status');
         	
         	foreach ($ordered_items as $item) {
         		$sku = $item->getSku();
         		$_product = Mage::getModel('catalog/product')->loadByAttribute('sku', $sku);
         		if ($_product) {
         			$_product = Mage::getModel('catalog/product')->load($_product->getId());
         			
         			//get config sku
         			if ($_product->getTypeId() == 'simple') {
         				$parentIds = Mage::getResourceSingleton('catalog/product_type_configurable')
                  ->getParentIdsByChild($_product->getId());
         				$conifg_product =  Mage::getModel('catalog/product')->load($parentIds[0]);			
         			} else {
         				$conifg_product = $_product;
         			}         
         			$config_sku = $conifg_product->getSku();
         			
         			//get third category name 
         			$categoryIds = $conifg_product->getCategoryIds();
         			foreach ($categoryIds as $cid) {
         				$cate = Mage::getModel('catalog/category')->load($cid);
         				
         				 if ($cate->getLevel() == 4) {
         				 	//get category name
         				 	$cate_name = $cate->getName();         	
         				 	$cate_name_parent =  Mage::getModel('catalog/category')->load($cate->getParentId());
         				 	
         				 
         				 	if ($cate_name_parent) {
         				 		//get gender
         				 		$gender_cate = Mage::getModel('catalog/category')->load($cate_name_parent->getParentId());	 
         				 		$gender = $gender_cate->getName();
         				 	}
         				 }         				
         			}
         			
         			//get en name
         			$en_name = $_product->getData('en_name');
         			//get size
         			$size = $_product->getAttributeText('size');
         			
         			//get qty
         			$qty = $item->getData('qty_ordered');
         			
         			//get original_price
         			$org_price = $_product->getData('price');
         			
         			//get sp price
         			$special_price = $_product->getSpecialPrice();
         			
         			//get row_total
         			$paid_amount =$item->getPrice() - $item->getDiscountAmount();
         			
         			//save into order object
         			$export_oder = Mage::getModel('export/order');
         			$export_oder->setData('order_increment_id', $order_increment_id);
         			$export_oder->setData('purchased_on',$purchased_on);
         			$export_oder->setData('ship_to_name', $shipping_to_name);
         			$export_oder->setData('status', $status);
         			$export_oder->setData('cate_name', $cate_name);
         			$export_oder->setData('gender', $gender);
         			$export_oder->setData('en_name', $en_name);
         			$export_oder->setData('config_sku', $config_sku);
         			$export_oder->setData('size', $size);
         			$export_oder->setData('qty', $qty);
         			$export_oder->setData('org_price',$org_price);
         			$export_oder->setData('special_price', $special_price);
         			$export_oder->setData('paid_amount', $paid_amount);
         			$export_oder->save();
         			var_dump('order:' . $order_increment_id . ' item id:' .$item->getId() . ' save successed!');        			
         		}
         		
         	}
         }
    }

}