SQL Server - Get all children of a row in many-to-many relationship?

I'm trying to write a recursive query in SQL Server that basically lists a parent-child hierarchy from a given parent. A parent can have multiple children and a child can belong to multiple parents so it is stored in a many-to-many relation.

I modified the following query from another somewhat related question, however this doesn't go all the way up to the tree and only selects the first level child...

DECLARE @ObjectId uniqueidentifier
SET @ObjectId = '1A213431-F83D-49E3-B5E2-42AA6EB419F1';

WITH Tree AS
(
   SELECT A.*
   FROM Objects_In_O开发者_运维问答bjects A
   WHERE A.ParentObjectId = @ObjectId

   UNION ALL

   SELECT B.*
   FROM Tree A
   JOIN Objects_In_Objects B
   ON A.ParentObjectId = B.ObjectId
)
SELECT *
FROM Tree
INNER JOIN Objects ar on tree.ObjectId = ar.ObjectId

Does anyone know how to modify the query to go all the way down the 'tree'? Or is this not possible using the above construction?

Objects

Columns: ObjectId | Name

Objects_In_Objects

Columns: ObjectId | ParentObjectId

Sample data:

Objects

ObjectId                             | Name
1A213431-F83D-49E3-B5E2-42AA6EB419F1 | Main container  
63BD908B-54B7-4D62-BE13-B888277B7365 | Sub container  
71526E15-F713-4F03-B707-3F5529D6B25E | Sub container 2  
ADA9A487-7256-46AD-8574-0CE9475315E4 | Object in multiple containers

Objects In Objects

ObjectId                             | ParentObjectId                    
ADA9A487-7256-46AD-8574-0CE9475315E4 | 71526E15-F713-4F03-B707-3F5529D6B25E
ADA9A487-7256-46AD-8574-0CE9475315E4 | 63BD908B-54B7-4D62-BE13-B888277B7365
63BD908B-54B7-4D62-BE13-B888277B7365 | 1A213431-F83D-49E3-B5E2-42AA6EB419F1
71526E15-F713-4F03-B707-3F5529D6B25E | 1A213431-F83D-49E3-B5E2-42AA6EB419F1

---

Such a recursive CTE (Common Table Expression) will goo all the way .

Try this:

;WITH Tree AS
(
   SELECT A.ObjectID, A.ObjectName, o.ParentObjectID, 1 AS 'Level'
   FROM dbo.Objects A
   INNER JOIN dbo.Objects_In_Objects o ON A.ObjectID = o.ParentObjectID
   WHERE A.ObjectId = @ObjectId           -- use the A.ObjectId here

   UNION ALL

   SELECT A2.ObjectID, A2.ObjectName, B.ParentObjectID, t.Level + 1 AS 'Level'
   FROM Tree t 
   INNER JOIN dbo.Objects_In_Objects B ON B.ParentObjectID = t.ObjectID
   INNER JOIN dbo.Objects A2 ON A2.ObjectId = B.ObjectId        
)
SELECT *
FROM Tree
INNER JOIN dbo.Objects ar on tree.ObjectId = ar.ObjectId

If you change this - does this work for you now? (I added a Level column - typically helps to understand the "depth" in the hierarchy for every row)

I do seem to get the proper output on my SQL Server instance, at least...

---

declare @Objects_In_Objects table
(
  ObjectID uniqueidentifier, 
  ParentObjectId uniqueidentifier
)

declare @Objects table
(
  ObjectId uniqueidentifier, 
  Name varchar(50)
)

insert into @Objects values
('1A213431-F83D-49E3-B5E2-42AA6EB419F1', 'Main container'),  
('63BD908B-54B7-4D62-BE13-B888277B7365', 'Sub container'),  
('71526E15-F713-4F03-B707-3F5529D6B25E', 'Sub container 2'),  
('ADA9A487-7256-46AD-8574-0CE9475315E4', 'Object in multiple containers')

insert into @Objects_In_Objects values
('ADA9A487-7256-46AD-8574-0CE9475315E4', '71526E15-F713-4F03-B707-3F5529D6B25E'),
('ADA9A487-7256-46AD-8574-0CE9475315E4', '63BD908B-54B7-4D62-BE13-B888277B7365'),
('63BD908B-54B7-4D62-BE13-B888277B7365', '1A213431-F83D-49E3-B5E2-42AA6EB419F1'),
('71526E15-F713-4F03-B707-3F5529D6B25E', '1A213431-F83D-49E3-B5E2-42AA6EB419F1')


DECLARE @ObjectId uniqueidentifier
SET @ObjectId = '1A213431-F83D-49E3-B5E2-42AA6EB419F1';

WITH Tree AS
(
   SELECT A.ObjectID,
          A.ParentObjectId
   FROM @Objects_In_Objects A
   WHERE A.ParentObjectId = @ObjectId

   UNION ALL

   SELECT B.ObjectID,
          B.ParentObjectId
   FROM Tree A
   JOIN @Objects_In_Objects B
   ON B.ParentObjectId = A.ObjectId
)
SELECT *
FROM Tree
INNER JOIN @Objects ar on tree.ObjectId = ar.ObjectId;

Is this what you are looking for? https://data.stackexchange.com/stackoverflow/q/111357/

---

Can this help you ?

http://www.aghausman.net/sql_server/storingretrieving-hierarchical-data-in-sql-server-database.html