Създаване на дървовидна заявка от таблица с числово съпоставяне в SQL (с поле за разделител)

Това трябва да ви приближи доста... Но трябва да призная, че не разбирам напълно логиката... Защо в 9401/Acc12 "HasChild" е зададено на 1?

Опитайте с това. Номерирането е разделено от SourceCast. Това означава, че и двата набора (или много набори се третират като един набор всеки, в зависимост от SourceCast. Освен това има работещ идентификатор, както във вашия пример:

CREATE TABLE Account(AccountID   NVARCHAR(50) NOT NULL
  ,AccountName NVARCHAR(50) NOT NULL
  ,SourceCast  INTEGER  NOT NULL
  ,PRIMARY KEY (AccountID,SourceCast));

 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11',N'Acc11',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'12',N'Acc12',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'13',N'Acc13',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11/11',N'Acc11/11',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11/12',N'Acc11/12',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11/111',N'Acc11/111',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11/11/001',N'Acc11/11/001',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'11/11/002',N'Acc11/11/002',9401);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15',N'Acc15',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'12',N'Acc12',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'13',N'Acc13',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15/15',N'Acc15/15',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15/12',N'Acc15/12',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15/111',N'Acc15/111',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15/15/001',N'Acc15/15/001',9402);
 INSERT INTO Account(AccountID,AccountName,SourceCast) VALUES (N'15/15/002',N'Acc15/15/002',9402);
GO

WITH DistinctSourceCasts AS (SELECT DISTINCT SourceCast FROM Account)
SELECT *
INTO #tempHierarchy
FROM
(
    SELECT SourceCast
          ,CAST(SourceCast AS NVARCHAR(50)) AS AccountID 
          ,CAST(SourceCast AS NVARCHAR(50)) AS AccountName
          ,0 AS ID
          ,0 AS HierarchyLevel
          ,'' AS ParentPath
          ,'' AS ownID
          ,'' AS ancestorID 
    FROM DistinctSourceCasts
    UNION ALL
    SELECT SourceCast
          ,AccountID
          ,AccountName
          ,ROW_NUMBER() OVER(PARTITION BY SourceCast ORDER BY LEN(AccountID)-LEN(REPLACE(AccountID,'/','')),AccountID) AS ID
          ,Extended.HierarchyLevel
          ,STUFF(
           (
             SELECT '/' + A.B.value('.','varchar(10)')
             FROM Extended.IDsXML.nodes('/x[position() <= sql:column("HierarchyLevel")]') AS A(B)
             FOR XML PATH('')
           ),1,2,'') AS ParentPath
          ,Extended.IDsXML.value('/x[sql:column("HierarchyLevel")+1][1]','varchar(10)') AS ownID
          ,Extended.IDsXML.value('/x[sql:column("HierarchyLevel")][1]','varchar(10)') AS ancestorID
    FROM Account
    CROSS APPLY(SELECT LEN(AccountID)-LEN(REPLACE(AccountID,'/','')) + 1 AS HierarchyLevel
                      ,CAST('<x></x><x>' + REPLACE(AccountID,'/','</x><x>') + '</x>' AS XML) AS IDsXML) AS Extended
) AS tbl;

UPDATE #tempHierarchy SET ParentPath = SourceCast,ancestorID=SourceCast WHERE HierarchyLevel=1;
UPDATE #tempHierarchy SET ownID=SourceCast WHERE HierarchyLevel=0;


WITH RecursiveCTE AS
(
    SELECT th.*
           ,CAST(NULL AS BIGINT) AS ParentID 
           ,CASE WHEN EXISTS(SELECT 1 FROM #tempHierarchy AS x WHERE x.ParentPath=th.AccountID) THEN 1 ELSE 0 END AS HasChild
    FROM #tempHierarchy AS th WHERE th.HierarchyLevel=0
    UNION ALL
    SELECT r.SourceCast
          ,sa.AccountID
          ,sa.AccountName
          ,sa.ID
          ,sa.HierarchyLevel
          ,sa.ParentPath
          ,sa.ownID
          ,sa.ancestorID
          ,(SELECT x.ID FROM #tempHierarchy AS x WHERE x.AccountID=sa.ParentPath)
          ,CASE WHEN EXISTS(SELECT 1 FROM #tempHierarchy AS x WHERE x.ParentPath=sa.AccountID) THEN 1 ELSE 0 END AS HasChild
    FROM RecursiveCTE AS r
    INNER JOIN #tempHierarchy AS sa ON sa.HierarchyLevel=r.HierarchyLevel+1 
                                       AND r.AccountID=sa.ParentPath
                                       AND r.SourceCast=sa.SourceCast
)
SELECT SourceCast
      ,r.AccountID
      ,r.AccountName
      ,ROW_NUMBER() OVER(ORDER BY SourceCast,HierarchyLevel,ParentID,ID) AS ID
      ,r.ID AS GroupedID
      ,r.ParentID
      ,r.HierarchyLevel
      ,r.HasChild
FROM RecursiveCTE AS r

DROP TABLE #tempHierarchy;

Резултатът:

+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| SourceCast | AccountID | AccountName  | ID | GroupedID | ParentID | HierarchyLevel | HasChild |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 9401      | 9401         | 1  | 0         | NULL     | 0              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11        | Acc11        | 2  | 1         | 0        | 1              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 12        | Acc12        | 3  | 2         | 0        | 1              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 13        | Acc13        | 4  | 3         | 0        | 1              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11/11     | Acc11/11     | 5  | 4         | 1        | 2              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11/111    | Acc11/111    | 6  | 5         | 1        | 2              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11/12     | Acc11/12     | 7  | 6         | 1        | 2              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11/11/001 | Acc11/11/001 | 8  | 7         | 4        | 3              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9401       | 11/11/002 | Acc11/11/002 | 9  | 8         | 4        | 3              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 9402      | 9402         | 10 | 0         | NULL     | 0              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 12        | Acc12        | 11 | 1         | 0        | 1              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 13        | Acc13        | 12 | 2         | 0        | 1              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15        | Acc15        | 13 | 3         | 0        | 1              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15/111    | Acc15/111    | 14 | 4         | 3        | 2              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15/12     | Acc15/12     | 15 | 5         | 3        | 2              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15/15     | Acc15/15     | 16 | 6         | 3        | 2              | 1        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15/15/001 | Acc15/15/001 | 17 | 7         | 6        | 3              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+
| 9402       | 15/15/002 | Acc15/15/002 | 18 | 8         | 6        | 3              | 0        |
+------------+-----------+--------------+----+-----------+----------+----------------+----------+