问题描述
我有一张如下所示的表格.
I have a table as shown below.
ID ParentID Node Name Node Type ------------------------------------------------------------------ 525 524 Root Area Level 1 526 525 C Area Level 2 527 525 A Area Level 2 528 525 D Area Level 2 671 525 E Area Level 2 660 527 B Area Level 3 672 671 F Area Level 3
如何编写递归 t-sql 查询以生成以下输出?
How can i write a recursive t-sql query to generate below output?
输出(输出中不需要根"节点):
Output ("Root" node not required in the output):
Node ID ----------------------- A 527 A/B 660 C 526 D 528 E 671 E/F 672
谢谢
推荐答案
查看 本页 使用公共表表达式.这就是我会使用的(假设您至少使用 SQL Server 2005)
Take a look at this page on using common table expressions. That is what I would use (assuming you are using at least SQL Server 2005)
这是使用您的案例的代码示例:
Here is a code example using your case:
WITH CTE (NodePath, ID) AS ( SELECT '/' + CAST(NodeName AS NVARCHAR(MAX)) AS NodePath, ID FROM TABLE WHERE NodeName = 'Root' UNION ALL SELECT CTE.NodePath + '/' + CAST(NodeName AS NVARCHAR(MAX)) AS NodePath, TABLE.ID FROM CTE INNER JOIN TABLE ON TABLE.ParentId = CTE.ID ) SELECT NodeName, ID FROM CTE