ECSHOP 商品详情页相关属性商品由新到旧排序

最新推荐文章于 2025-09-12 13:16:34 发布

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最新推荐文章于 2025-09-12 13:16:34 发布

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CC 4.0 BY-SA版权

文章标签： php

原文链接：http://www.cnblogs.com/wangblognet/archive/2012/12/20/2826166.html

本文介绍了如何优化电子商务网站中用于查找符合条件商品的SQL查询语句，通过修改查询条件和使用DISTINCT关键字，提高了数据检索效率。文章详细解释了原始查询与优化后查询的区别，并提供了实际应用案例。

打开文件 includes/lib_goods.php

查找以下代码

            /* 查找符合条件的商品 */
            $sql = 'SELECT g.goods_id, g.goods_name, g.goods_thumb, g.goods_img, g.shop_price AS org_price, ' .
                        "IFNULL(mp.user_price, g.shop_price * '$_SESSION[discount]') AS shop_price, ".
                        'g.market_price, g.promote_price, g.promote_start_date, g.promote_end_date ' .
                    'FROM ' . $GLOBALS['ecs']->table('goods') . ' AS g ' .
                    'LEFT JOIN ' . $GLOBALS['ecs']->table('goods_attr') . ' as a ON g.goods_id = a.goods_id ' .
                    "LEFT JOIN " . $GLOBALS['ecs']->table('member_price') . " AS mp ".
                        "ON mp.goods_id = g.goods_id AND mp.user_rank = '$_SESSION[user_rank]' ".
                    "WHERE a.attr_id = '$key' AND g.is_on_sale=1 AND a.attr_value = '$val[value]' AND g.goods_id <> '$_REQUEST[id]' " .
                    'LIMIT ' . $GLOBALS['_CFG']['attr_related_number'];
            $res = $GLOBALS['db']->getAll($sql);

修改成

            /* 查找符合条件的商品 */
            $sql = 'SELECT DISTINCT  g.goods_id, g.goods_name, g.goods_thumb, g.goods_img, g.shop_price AS org_price, ' .
                        "IFNULL(mp.user_price, g.shop_price * '$_SESSION[discount]') AS shop_price, ".
                        'g.market_price, g.promote_price, g.promote_start_date, g.promote_end_date ' .
                    'FROM ' . $GLOBALS['ecs']->table('goods') . ' AS g ' .
                    'LEFT JOIN ' . $GLOBALS['ecs']->table('goods_attr') . ' as a ON g.goods_id = a.goods_id ' .
                    "LEFT JOIN " . $GLOBALS['ecs']->table('member_price') . " AS mp ".
                        "ON mp.goods_id = g.goods_id AND mp.user_rank = '$_SESSION[user_rank]' ".
                    "WHERE a.attr_id = '$key' AND g.is_on_sale=1 AND a.attr_value = '$val[value]' AND g.goods_id <> '$_REQUEST[id]' " .
                    ' ORDER BY  g.goods_id  DESC ' . ' LIMIT ' . $GLOBALS['_CFG']['attr_related_number'];
            $res = $GLOBALS['db']->getAll($sql);