SQL递归查询

Question

我有一个表类别，

1) Id
2) 类别名称
3) CategoryMaster

，数据为：

1 电脑 0
2 软件1
3 多媒体1
4 动画3
5 健康 0
6 Healthsub 5

和我创建了递归查询：

 ;WITH CategoryTree AS
 (
  SELECT *, CAST(NULL AS VARCHAR(50)) AS ParentName, 0 AS Generation    
  FROM dbo.Category    
  WHERE CategoryName = 'Computers'

  UNION ALL        

  SELECT Cat.*,CategoryTree.CategoryName AS ParentName, Generation + 1    
  FROM dbo.Category AS Cat  INNER JOIN 
  CategoryTree ON Cat.CategoryMaster = CategoryTree.Id
 )

 SELECT * FROM CategoryTree

我从父类别到底部获得结果，就像我获得计算机的所有子类别一样，

但我想要从下到上的结果，例如从动画到计算机，请一些有人建议我正确的方向。

先感谢您 ：）

Answer 1

只需交换 join 子句中的字段即可：

WITH CategoryTree AS
        (
        SELECT  *, 0 AS Generation    
        FROM    dbo.Category
        WHERE   CategoryName = 'Animation'
        UNION ALL
        SELECT  Cat.*, Generation + 1    
        FROM    CategoryTree
        JOIN    dbo.Category AS Cat
        ON      Cat.Id = CategoryTree.CategoryMaster
        )
SELECT  *
FROM    CategoryTree