EC CUBE 注文関連テーブルを削除

<?php
$this->objQuery->delete( 'dtb_mail_history' );
$this->objQuery->delete( 'dtb_order_temp' );
$this->objQuery->delete( 'dtb_order' );
$this->objQuery->delete( 'dtb_order_detail' );
$this->objQuery->delete( 'dtb_shipping' );
$this->objQuery->delete( 'dtb_shipment_item' );