使用SQLSERVER 2005/2008 递归CTE查询树型结构的方法

下面是一个简单的Family Tree 示例:


复制代码 代码如下:

DECLARE @TT TABLE (ID int,Relation varchar(25),Name varchar(25),ParentID int)

INSERT @TT SELECT 1,’ Great GrandFather’ , ‘Thomas Bishop’, null UNION ALL

SELECT 2,’Grand Mom’, ‘Elian Thomas Wilson’ , 1 UNION ALL

SELECT 3, ‘Dad’, ‘James Wilson’,2 UNION ALL

SELECT 4, ‘Uncle’, ‘Michael Wilson’, 2 UNION ALL

SELECT 5, ‘Aunt’, ‘Nancy Manor’, 2 UNION ALL

SELECT 6, ‘Grand Uncle’, ‘Michael Bishop’, 1 UNION ALL

SELECT 7, ‘Brother’, ‘David James Wilson’,3 UNION ALL

SELECT 8, ‘Sister’, ‘Michelle Clark’, 3 UNION ALL

SELECT 9, ‘Brother’, ‘Robert James Wilson’, 3 UNION ALL

SELECT 10, ‘Me’, ‘Steve James Wilson’, 3

———-Query—————————————

;WITH FamilyTree

AS(

SELECT *, CAST(NULL AS VARCHAR(25)) AS ParentName, 0 AS Generation FROM @TT

WHERE ParentID IS NULL

UNION ALL

SELECT Fam.*,FamilyTree.Name AS ParentName, Generation + 1 FROM @TT AS Fam

INNER JOIN FamilyTree ON Fam.ParentID = FamilyTree.ID

)SELECT * FROM FamilyTree

Output:

希望对您有帮助

Author: Petter Liu

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