SQL recursive query
I h开发者_运维问答ave a Table Category,
1) Id
2) CategoryName 3) CategoryMasterwith data as:
1 Computers 0 2 Software 1 3 Multimedia 1 4 Animation 3 5 Health 0 6 Healthsub 5and i have created recursive query as:
;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
I get the results for parent category to bottom, like i get all sub categories for computer
but i want the results from bottom-up like from Animation to Computers, please can some one suggest me right direction.
Thank you in advance :)
Just swap the fields in the join clause:
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
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