小编use*_*826的帖子

我有一个表保存用户评论,我想检索每个用户发表的最后一条评论.

下面的查询应该让我知道我想要做什么

select comment, comment_id, userId FROM comments_table 
WHERE comment_id in (
   SELECT MAX(comment_id)
   FROM comments_table where userId in (2001, 2002, 2010)
   GROUP BY userId
)

以上查询有效,但需要太长时间,特别是如果有很多userIds.

我需要一个更快的查询语句来完成同样的事情.

我在我的magento 1.7商店安装了扩展CreativeStyle CheckoutByAmazon,我试图覆盖CheckoutController类但是magento似乎忽略了我的覆盖.任何建议将不胜感激.还清除缓存但仍然无法正常工作

(在app/code/local文件夹中)

MyModule\CheckoutByAmazon\controllers\CheckoutController.php\etc\config.xml

(应用程序的/ etc/config.xml中)

<?xml version="1.0" encoding="UTF-8"?>
<config>
    <modules>
        <MyModule_CheckoutByAmazon>
            <version>0.1.0</version>
        </MyModule_CheckoutByAmazon>
    </modules>
    <frontend>
        <routers>
            <checkoutbyamazon>
                <args>
                    <modules>
                        <MyModule_CheckoutByAmazon before="Creativestyle_CheckoutByAmazon">MyModule_CheckoutByAmazon</MyModule_CheckoutByAmazon>
                    </modules>
                </args>
            </checkoutbyamazon>
        </routers>
    </frontend>
</config>

(在app/code/local/MyModule/CheckoutByAmazon/controllers/CheckoutController中)

<?php
//Controllers are not autoloaded so we will have to do it manually:
require_once 'Creativestyle/CheckoutByAmazon/controllers/CheckoutController.php';

class MyModule_CheckoutByAmazon_CheckoutController extends Creativestyle_CheckoutByAmazon_CheckoutController {

    public function indexAction() {
       exit('I am here');
        parent::indexAction();
    }

    //i want to override this function
      public function saveShippingAction() {
       //insert my overriding code
        exit('saveShipping');
        }

}
?>

(在etc/modules/MyModule_CheckoutByAmazon.xml中)

<?xml version="1.0"?> …