父子表的Sql脚本

Question

我有一张桌子：

ID  ParentID
3   1
7   2
4   3
5   4

如何使用sql脚本（递归方式）列出结果如下：

ID  ParentID
3   1
4   3
5   4
7   2

你有什么想法吗？

Answer 1

SELECT * FROM YourTable ORDER BY ID会为您提供所需的订单。但如果你想要递归的那个：

SELECT childs.Id AS 'Child Id', Parents.Id As 'Parent'
FROM YourTable childs
INNER JOIN YourTable parents ON childs.ParentId = parents.Id
ORDER BY Parents.Id

Answer 2

Select * 
from MyTable 
order By ID;

Answer 3

Select * from tablename order by id