优化 SELECT a.item_id, a.item_code, a.item_name, GROUP_CONCAT(b.channel_class_code) channelClassCodes, (SELECT count(*) FROM `tb_user_collection` where user_id = #{skuGoodDto.userId} and target_id = a.item_code) AS isCollect FROM osy_item AS a LEFT JOIN osy_item_sale AS b ON a.item_id = b.item_id where a.usable = 2 and b.usable = 2 and (b.channel_class_code = 10 or b.channel_class_code = 22) GROUP BY a.item_id

根据您提供的 SQL 查询语句，可以对其进行一些优化。首先，可以使用 IN 关键字来简化 WHERE 子句中的多个条件判断，将

(b.channel_class_code = 10 or b.channel_class_code = 22)

修改为

b.channel_class_code IN (10, 22)

接下来，可以使用 LEFT JOIN 连接 osy_item 和 osy_item_sale 表，然后再使用 GROUP BY 子句对结果进行分组。这样可以避免在 SELECT 子查询中使用子查询。

下面是优化后的 SQL 查询语句：

SELECT a.item_id,
       a.item_code,
       a.item_name,
       GROUP_CONCAT(b.channel_class_code) AS channelClassCodes,
       COUNT(c.target_id) AS isCollect
FROM osy_item AS a
LEFT JOIN osy_item_sale AS b ON a.item_id = b.item_id
LEFT JOIN tb_user_collection AS c ON c.target_id = a.item_code AND c.user_id = #{skuGoodDto.userId}
WHERE a.usable = 2
      AND b.usable = 2
      AND b.channel_class_code IN (10, 22)
GROUP BY a.item_id;

请注意，上述 SQL 查询语句中的 `#{skuGoodDto.userId}` 是占位符，您需要根据实际情况将其替换为相应的用户 ID 值。