摘要: 1、第一种写法 select id, case when p_id is null then "Root" when id not in (select distinct p_id from Tree where p_id is not null) then "Leaf" else "Inner" 阅读全文
posted @ 2023-11-03 14:55 先娶国王后取经 阅读(8) 评论(0) 推荐(0) 编辑