CTE genitore-figlio che mostra fratelli

Question

Ho una query CTE che visualizza un albero utilizzando la ricorsione. Funziona alla grande quando si visualizza l'intero albero. Ma voglio passare in ID come variabile e includere i fratelli per ogni nodo corrente.

Testcode:

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

INSERT @TT 
SELECT 1, 'A', NULL, 1 UNION ALL 
SELECT 2, 'B_1', 3, 1 UNION ALL 
SELECT 3, 'B', 1, 2 UNION ALL 
SELECT 4, 'B_2', 3, 2 UNION ALL 
SELECT 5, 'C', 1, 3 UNION ALL 
SELECT 6, 'C_2', 5, 2 UNION ALL 
SELECT 7, 'A_1', 1, 1 UNION ALL 
SELECT 8, 'A_2', 1, 2 UNION ALL 
SELECT 9, 'C_1', 5, 1 


;WITH CTETree 
AS 
(
    SELECT *, CAST(NULL AS VARCHAR(25)) AS ParentName, 1 AS Lev, 
    CAST(ROW_NUMBER() OVER(ORDER BY SortIndex) AS VARBINARY(MAX)) AS SortPath 
    FROM @TT 
    WHERE ParentID IS NULL 

    UNION ALL 

    SELECT F.*, CTETree.Name AS ParentName, Lev + 1, 
    SortPath + CAST(ROW_NUMBER() OVER(ORDER BY F.SortIndex) AS BINARY(32)) 
    FROM @TT AS F 
    INNER JOIN CTETree 
    ON F.ParentID = CTETree.ID 
) 

SELECT * FROM CTETree 
    ORDER BY SortPath 

/* 
DESIRED RESULT: 

WHEN ID = 3 PASSED IN: 

1 A NULL 1 NULL 1 
3 B 1 2 A 2 
2 B_1 3 1 B 3 
4 B_2 3 2 B 3 
5 C 1 3 A 2 

WHEN ID = 1 PASSED IN: 

1 A NULL 1 NULL 1 
3 B 1 2 A 2 
5 C 1 3 A 2 

WHEN ID = 9 PASSED IN: 

1 A NULL 1 NULL 1 
3 B 1 2 A 2 
5 C 1 3 A 2 
9 C_1 5 1 C 3 
6 C_2 5 2 C 3 

*/ 

SQL-Fiddle: http://sqlfiddle.com/#!3/d41d8/5526

Answer 1

Solo una volta mi confronto una domanda in cui scompaiono A_1 e A_2. Quindi aggiungere un'eccezione (nel caso clausola). Se avete bisogno di cancellare i risultati questa espressione e f.ID! = 7 E f.ID! = 8.

DECLARE @ID int = 3 -- variable wich you want pass 
DECLARE @Matched int = (SELECT CASE WHEN ParentID = 1 THEN ID ELSE ParentID END FROM @TT WHERE ID = @ID) 
;WITH CTETree 
AS 
(
SELECT *, CAST(NULL AS VARCHAR(25)) AS ParentName, 1 AS Lev, 
     CAST(ROW_NUMBER() OVER(ORDER BY SortIndex) AS VARBINARY(MAX)) AS SortPath, 
     0 AS Matched 
FROM @TT 
WHERE ParentID IS NULL 
UNION ALL 
SELECT F.*, cte.Name AS ParentName, cte.Lev + 1, 
     SortPath + CAST(ROW_NUMBER() OVER(ORDER BY F.SortIndex) AS BINARY(32)), 
     CASE WHEN (cte.ID = 1 AND f.ID != 7 AND f.ID != 8) 
     OR (cte.ID = @Matched AND cte.Lev + 1 > 2) 
     THEN 1 END AS Matched 
FROM @TT AS F INNER JOIN CTETree cte 
ON F.ParentID = cte.ID 
) 
SELECT ID, Name, ParentID, SortIndex, ParentName, Lev FROM CTETree 
WHERE Matched IS NOT NULL 
ORDER BY SortPath 

Demo SQLFiddle