选择对象在Zend framework中具有__toString（）方法。
从Zend framework手册中：
$select = $db->select() ->from('products');$sql = $select->__toString();echo "$sqln";// The output is the string:// SELECT * FROM "products"另一种解决方案是使用Zend_Db_Profiler。即
$db->getProfiler()->setEnabled(true);// your pre$this->update($up_value,'customer_id ='.$userid.' and address_id <> '.$data['address_Id']);Zend_Debug::dump($db->getProfiler()->getLastQueryProfile()->getQuery());Zend_Debug::dump($db->getProfiler()->getLastQueryProfile()->getQueryParams());$db->getProfiler()->setEnabled(false);
http://framework.zend.com/manual/zh/zend.db.select.html
