欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

单纯MYSQL递归查询上下级关系

程序员文章站 2024-03-21 13:18:58
...

查询 id = 6 的所有父级

SELECT ID.level, DATA.* FROM( 
SELECT 
@id as _id, 
( SELECT @id := parent_id 
FROM table1 
WHERE id = @id 
) as _pid, 
@l := @l+1 as level 
FROM table1, 
(SELECT @id := 6, @l := 0 ) b 
WHERE @id > 0 
) ID, table1 DATA 
WHERE ID._id = DATA.id 
ORDER BY level;

根据这个父级查询方法,很容易可以写出查所有子级的,下面的查询 id=3 的所有子级
SELECT ID.level, DATA.* FROM( 
SELECT 
@ids as _ids, 
( SELECT @ids := GROUP_CONCAT(id) 
FROM table1 
WHERE FIND_IN_SET(parent_id, @ids) 
) as cids, 
@l := @l+1 as level 
FROM table1, 
(SELECT @ids :=3, @l := 0 ) b 
WHERE @ids IS NOT NULL 
) id, table1 DATA 
WHERE FIND_IN_SET(DATA.id, ID._ids) 
ORDER BY level, id