SQL递归查询实现跟帖盖楼效果
网易新闻的盖楼乐趣多,某一天也想实现诸如网易新闻跟帖盖楼的功能,无奈技术不佳(基础不牢),网上搜索了资料才发现SQL查询方法有一种叫递归查询,整理如下:
一、查询出 id = 1 的所有子结点
with my1 as (select * from table where id = 1 union all select table.* from my1, table where my1.id = table.fatherId) select * from my1
结果包含1这条记录,如果不想包含,可以在最后加上:where id <> 1
二、查询出 id = 2 的所有父结点
with my1 as (select * from table where id = 2 union all select table.* from my1, table where my1.fatherId = table.id ) select * from my1;
三、删除 id = 1 的所有子结点(包括id = 1结点)
with my1 as (select * from table where id = 1 union all select table.* from my1, table where my1.id = table.fatherId ) delete from table where exists (select id from my1 where my1.id = table.id)
本文摘自木庄网络博客>>SQL递归查询实现跟帖盖楼效果
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