MySql分层查询

问题描述

我有“组织”表：

Id  Name  ParentId
------------------
 1  Org1         5
 2  Org2         5
 3  Org3         4
 4  Depart2      6
 5  Depart1      6
 6  Company   null

我想实现的是返回表的查询每个组织在层次结构树中都属于较高级别的组织单位：

Id    BelongsToOrgId
1     1                  Org1 is part of Org1
1     5                  Org1 is part of Depart1  
1     6                  Org1 is part of Company
2     2                  Org2 is part of Org2
2     5                  Org2 is part of Depart1
2     6                  Org2 is part of Company
3     3                  Org3 is part of Org3
3     4                  Org3 is part of Depart2
3     6                  Org3 is part of Company
4     4                  Depart2 is part of Depart2 
4     6                  Depart2 is part of Company 
5     5                  Depart1 is part of Depart1  
5     6                  Depart1 is part of Company
6     6                  Company is part of Company

最好的问候，皮奥特

解决方法

WITH RECURSIVE
cte AS ( SELECT Id,Name,id BelongsToOrgId,Name UpperName
         FROM Organizations 
       UNION ALL
         SELECT Organizations.Id,Organizations.Name,cte.BelongsToOrgId,cte.Name
         FROM Organizations 
         JOIN cte ON Organizations.ParentId = cte.Id )
SELECT Id,BelongsToOrgId,CONCAT(Name,' is part of ',UpperName) Relation
FROM cte
ORDER BY Id,BelongsToOrgId;

fiddle

感谢Akina，

我们快到了，一个解决方法：

WITH RECURSIVE
cte AS ( SELECT Id,cte.UpperName
         FROM Organizations 
         JOIN cte ON Organizations.ParentId = cte.Id )
SELECT Id,BelongsToOrgId;

第5行是cte.UpperName，而不是cte.Name

hierarchical mysql recursion