mysql本身不支持递归语法，但可通过自连接变相实现一些简单的递归，本文主要介绍了mysql之递归小问题,需要的朋友可以参考下，希望能帮助到大家。
--递归小方法：临时表和普通表的不同方法 --这题使用的是2次临时表查询父节点的递归 drop table if exists test; create table test( id varchar(100), name varchar(20), parentid varchar(100) ); insert test select '13ed38f1-3c24-dd81-492f-673686dff0f3', '大学教师', '37e2ea0a-1c31-3412-455a-5e60b8395f7d' union all select '1ce203ac-ee34-b902-6c10-c806f0f52876','小学教师', '37e2ea0a-1c31-3412-455a-5e60b8395f7d' union all select '37e2ea0a-1c31-3412-455a-5e60b8395f7d', '教师' , null union all select 'c877b7ea-4ed3-f472-9527-53e1618cb1dc', '高数老师', '13ed38f1-3c24-dd81-492f-673686dff0f3' union all select 'ce50a471-2955-00fa-2fb7-198f6b45b1bd', '中学教师', '37e2ea0a-1c31-3412-455a-5e60b8395f7d'; delimiter $$ create procedure usp_ser(in idd varchar(100)) begin declare lev int; set lev=1; drop table if exists tmp1; drop table if exists tmp2; CREATE TEMPORARY TABLE tmp1(id varchar(100),name varchar(20),parentid varchar(100),levv int); CREATE TEMPORARY TABLE tmp2(pid varchar(100)); insert tmp2 select parentid from test where id=idd; insert tmp1 select t.* , lev from test t join tmp2 a on t.id=a.pid; while exists(select 1 from tmp2 ) do truncate tmp2; set lev=lev+1; insert tmp2 select t.id from test t join tmp1 a on t.id=a.parentid and a.levv=lev-1; insert tmp1 select t.*,lev from test t join tmp2 a on t.id=a.pid; end while ; select id,name,parentid from tmp1; end; $$ delimiter ; call usp_ser('c877b7ea-4ed3-f472-9527-53e1618cb1dc'); +--------------------------------------+----------+--------------------------------------+ | id | name | parentid | +--------------------------------------+----------+--------------------------------------+ | 13ed38f1-3c24-dd81-492f-673686dff0f3 | 大学教师 | 37e2ea0a-1c31-3412-455a-5e60b8395f7d | | 37e2ea0a-1c31-3412-455a-5e60b8395f7d | 教师 | NULL | +--------------------------------------+----------+--------------------------------------+ call usp_ser('13ed38f1-3c24-dd81-492f-673686dff0f3'); +--------------------------------------+------+----------+ | id | name | parentid | +--------------------------------------+------+----------+ | 37e2ea0a-1c31-3412-455a-5e60b8395f7d | 教师 | NULL | +--------------------------------------+------+----------+ call usp_ser('37e2ea0a-1c31-3412-455a-5e60b8395f7d'); Empty set (0.02 sec)
上面的方法因为由于MySQL中不允许在同一语句中对临时表多次引用，所以用2次临时表
下面给个一次性用普通表完成的 查询子节点的递归查询
核心代码
drop table if exists test; create table test( id INT, parentid INT ); insert test select 1, 0 UNION ALL SELECT 2, 1 UNION ALL SELECT 3, 1 UNION ALL SELECT 4, 0 UNION ALL SELECT 5, 2 UNION ALL SELECT 6, 5 UNION ALL SELECT 7, 3 ; Go delimiter $$ create procedure usp_ser(in idd varchar(100)) begin declare lev int; set lev=1; drop table if exists tmp1; CREATE TABLE tmp1(id INT,parentid INT ,levv INT,ppath VARCHAR(1000)); INSERT tmp1 SELECT *,lev,id FROM test WHERE parentid=idd; while row_count()>0 do set lev=lev+1; insert tmp1 select t.*,lev,concat(a.ppath,t.id) from test t join tmp1 a on t.parentid=a.id AND levv=LEV-1; end while ; SELECT * FROM tmp1; end; $$ delimiter ; call usp_ser(0); /* +------+----------+------+-------+ | id | parentid | levv | ppath | +------+----------+------+-------+ | 1 | 0 | 1 | 1 | | 4 | 0 | 1 | 4 | | 2 | 1 | 2 | 12 | | 3 | 1 | 2 | 13 | | 5 | 2 | 3 | 125 | | 7 | 3 | 3 | 137 | | 6 | 5 | 4 | 1256 | +------+----------+------+-------+*/
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