consulta recursiva t-sql

Question

Basado en una tabla existente utilicé la consulta recursiva CTE para obtener los siguientes datos. Pero no aplicarlo un nivel más allá.

de datos es la siguiente

id name  parentid 
-------------------------- 
1  project 0 
2  structure 1 
3  path_1 2 
4  path_2 2 
5  path_3 2 
6  path_4 3 
7  path_5 4 
8  path_6 5 

quiero formar de forma recursiva rutas completas a partir de los datos anteriores. Significa que la recursión dará la siguiente salida.

FullPaths 
------------- 
Project 
Project\Structure 
Project\Structure\Path_1 
Project\Structure\Path_2 
Project\Structure\Path_3 
Project\Structure\Path_1\path_4 
Project\Structure\Path_2\path_5 
Project\Structure\Path_3\path_6 

Gracias

Answer 1

He aquí un ejemplo de CTE para hacer eso:

declare @t table (id int, name varchar(max), parentid int) 

insert into @t select 1,  'project' , 0 
union all select 2,  'structure' , 1 
union all select 3,  'path_1' , 2 
union all select 4,  'path_2' , 2 
union all select 5,  'path_3' , 2 
union all select 6,  'path_4' , 3 
union all select 7,  'path_5' , 4 
union all select 8,  'path_6' , 5 

; with CteAlias as (
    select id, name, parentid 
    from @t t 
    where t.parentid = 0 
    union all 
    select t.id, parent.name + '\' + t.name, t.parentid 
    from @t t 
    inner join CteAlias parent on t.parentid = parent.id 
) 
select * 
from CteAlias 

Answer 2

Algo así como

;WITH MyCTE AS 
(
    SELECT 
     name AS FullPaths, id 
    FROM 
     MyTable 
    WHERE 
     parentid = 0 /*Normally it'd be IS NULL with an FK linking the 2 columns*/ 
    UNION ALL 
    SELECT 
     C.FullPaths + '\' + M.name, M.id 
    FROM 
     MyCTE C 
     JOIN 
     MyTable M ON M.parentid = C.id 
) 
SELECT FullPaths FROM MyCTE 

Answer 3

intente esto:

DECLARE @YourTable table (id int, nameof varchar(25), parentid int) 
INSERT @YourTable VALUES (1,'project',0) 
INSERT @YourTable VALUES (2,'structure',1) 
INSERT @YourTable VALUES (3,'path_1',2) 
INSERT @YourTable VALUES (4,'path_2',2) 
INSERT @YourTable VALUES (5,'path_3',2) 
INSERT @YourTable VALUES (6,'path_4',3) 
INSERT @YourTable VALUES (7,'path_5',4) 
INSERT @YourTable VALUES (8,'path_6',5) 

;WITH Rec AS 
(
    SELECT 
     CONVERT(varchar(max),nameof) as nameof,id 
     FROM @YourTable 
     WHERE parentid=0 
    UNION ALL 
    SELECT 
     CONVERT(varchar(max),r.nameof+'\'+y.nameof), y.id 
     FROM @yourTable y 
      INNER jOIN Rec r ON y.parentid=r.id 
) 
select * from rec 

de salida:

nameof           
----------------------------------------------- 
project           
project\structure        
project\structure\path_1      
project\structure\path_2      
project\structure\path_3      
project\structure\path_3\path_6     
project\structure\path_2\path_5     
project\structure\path_1\path_4     

(8 row(s) affected) 

Answer 4

intentar algo como esto:

WITH Recursive AS 
(
    SELECT 
     ID, 
      CAST(PathName AS VARCHAR(500)) AS 'FullPaths', 
      1 AS 'Level' 
    FROM 
     dbo.YourTable 
    WHERE 
     ParentID = 0 

    UNION ALL 

    SELECT 
     tbl.ID, 
      CAST(r.FullPaths + '\' + tbl.PathName AS VARCHAR(500)) AS 'FullPaths', 
      r.Level + 1 AS 'Level' 
    FROM 
     dbo.YourTable tbl 
    INNER JOIN 
     Recursive r ON tbl.ParentID = r.ID 
) 
SELECT * FROM Recursive 
ORDER BY Level, ID 

Salida:

ID FullPaths     Level 
1 project       1 
2 project\structure     2 
3 project\structure\path_1   3 
4 project\structure\path_2   3 
5 project\structure\path_3   3 
6 project\structure\path_1\path_4 4 
7 project\structure\path_2\path_5 4 
8 project\structure\path_3\path_6 4 

Answer 5

Vas a tener que cambiar el nombre de la tabla #test que estaba usando.

WITH cte(id, name, parentid) AS 
(
    SELECT id, convert(varchar(128), name), parentid 
    FROM #test 
    WHERE parentid = 0 
    UNION ALL 
    SELECT t.id, convert(varchar(128), c.name +'\'+t.name), t.parentid 
    FROM #test t 
    INNER JOIN cte c 
    ON c.id = t.parentid 
) 
SELECT name as FullPaths 
FROM cte 
order by id