最近在做ecshop二次开发，在给商品增加一个字段排序的时候用到三表查询更新。

（1）在SQLyog Community测试时候的SQL语句：

UPDATE `ecs_goods` AS d SET d.salesnum=
(SELECT c.salesnum 
 FROM
       (SELECT a.goods_id,a.goods_name,b.salesnum 
FROM 
(SELECT goods_id, goods_name, goods_type, goods_sn, shop_price, is_on_sale, is_best, is_new, is_hot, sort_order,recommend_status,
recommend_point,themeid,marcket_lprice,shop_lprice, goods_number, integral, 
(promote_price > 0 AND promote_start_date <= '1353686399' AND promote_end_date >= '1353686399') AS is_promote 
FROM `eshop`.`ecs_goods` AS g WHERE is_delete='0' AND is_real='1') 
AS a,
(SELECT goods_id,goods_name,COUNT(*) AS salesnum 
FROM `ecs_order_goods` WHERE order_id IN ('20','21','22','25','26','27','28','29','30','31','32','33','34','35','36','37','38',
 '39','40','41','42','43','44','45','46','47','48','49','50','51','52','53','54','55',
 '56','57','58','59','60','61','62','63','64','65','66','67','68','69','70','71','72',
 '73','74','75','76','77','78','79','80','81','82','83','84','85','86','87','88','89',
 '90','91','92','93','94','95','96','97','98','99','100','101','102','103','104','105',
 '106','107','108','109','110','111','112','113','114','115','116','117','118','119','120',
 '121','122','123','124','125','126','127','128','129','130','131','132','133','134','135',
 '136','139','140','141','142','143','144','145','146','147','148','149','150','151','152',
 '153','157','158','159','161','162','163','164')  GROUP BY goods_id,goods_name) 
AS b 
WHERE a.goods_id=b.goods_id) 
 AS c 
 WHERE c.goods_id=d.goods_id
);

（2）在ecshop代码里面的SQL语句：

$sql = "UPDATE " . $GLOBALS['ecs']->table('ecs_goods') . " AS d SET d.salesnum=
(SELECT c.salesnum FROM
      (SELECT a.goods_id,a.goods_name,b.salesnum 
FROM 
(SELECT goods_id, goods_name, goods_type, goods_sn, shop_price, is_on_sale, is_best, is_new, is_hot, sort_order,recommend_status,
recommend_point,themeid,marcket_lprice,shop_lprice, goods_number, integral, 
(promote_price > 0 AND promote_start_date <= '$today' AND promote_end_date >= '$today') AS is_promote 
FROM " . $GLOBALS['ecs']->table('goods') . " AS g WHERE is_delete='$is_delete' $where) 
AS a,
(SELECT goods_id,goods_name,COUNT(*) AS salesnum 
FROM `ecs_order_goods` WHERE order_id ".db_create_in($order_id_arr)." GROUP BY goods_id,goods_name) 
AS b 
WHERE a.goods_id=b.goods_id) AS c WHERE c.goods_id=d.goods_id
)";

（3）最后打印出来的SQL语句：

UPDATE `