mysql 实际应用场景case...when

背景：同事有个需求，需要按照某个字段的值划分区间，之后按照区间进行排序。第一反应是用if，后来想想if有点没转出来，就改成case...when了

SELECT goods_id, sort_order,
CASE
WHEN sort_order IS NULL THEN 0
WHEN sort_order < 80  THEN 1
WHEN sort_order BETWEEN 80 and 160 THEN 2
ELSE 3
END AS order_level
FROM ecm_market_activity_apply
WHERE goods_id > 0
ORDER BY order_level DESC,sort_order DESC

因为sql语句中用到了between...and，又有同事说between...and可能比<=,>=这样慢一些，于是用mysql的explain分析了两条sql

EXPLAIN SELECT * FROM ecm_goods WHERE goods_id BETWEEN 290000 AND 310000

EXPLAIN SELECT * FROM ecm_goods WHERE goods_id >= 290000 AND goods_id <= 310000

解析后的图如上，结论的话就见仁见智吧(我请教的大神说，sql分析一样，效率就应该是一样的，不会有区别)。