CREATE TABLE TB001
(
CategoryId INT PRIMARY KEY,
ParentCategoryId INT,
CategoryName NVARCHAR(200)
)
GO
WITH T
AS
(
SELECT T1.CategoryId,
T1.CategoryName,
T1.ParentCategoryId,
0 AS CategoryLevel
FROM TB001 AS T1
WHERE T1.ParentCategoryId IS NULL
UNION ALL
SELECT T1.CategoryId,
T1.CategoryName,
T1.ParentCategoryId,
T.CategoryLevel+1 AS CategoryLevel
FROM TB001 AS T1
INNER JOIN T ON T1.ParentCategoryId=T.CategoryId
)
SELECT *
FROM T
OPTION(MAXRECURSION 2)
--Note：注意控制最大递归数