Conditional Recursive SQL Select - sql

Question

Consider the following database table. It consists of 3 columns: Id, ParentId, Enabled.
I would like to produce a result set similar to the following. Basically for each record that has a Parent ID, I want to to display an additional column Enabled Parent Id. This column basically needs to recursively checks the hierarchy of the key, and stops when a key that is Enabled = True is found.
I would like this to achieve this on the fly, without requiring to add any additional computed columns in the table.
Maybe this could be achieved using a CTE.

Answer 1

Try this CTE query:
WITH T1 as
(SELECT id,
parentId,
NULL as EnabledParentId,
ParentID as NextParent
FROM T
WHERE ParentID is not null
UNION ALL
SELECT T1.id,
T1.parentId,
CASE WHEN T.enabled = 1
THEN T.ID
ELSE NULL END
as EnabledParentId,
T.ParentID as NextParent
FROM T1
JOIN T ON T1.NextParent = T.Id
WHERE (nextParent is not Null) and (EnabledParentId IS NULL)
)
SELECT ID,
ParentID,
EnabledParentID
FROM T1
WHERE EnabledParentId IS NOT NULL
OR NextParent IS NULL
ORDER BY ID;

Answer 2

DECLARE #myTable TABLE
(
Id INT NOT NULL,
ParentId INT NOT NULL,
EnabledParentId INT
)
DECLARE myCursor CURSOR FOR
SELECT Id
FROM T
WHERE ParentId IS NOT NULL
ORDER BY Id;
OPEN myCursor;
DECLARE #currentId INT;
FETCH NEXT FROM myCursor INTO #currentId;
WHILE ##FETCH_STATUS = 0
BEGIN
DECLARE #Exists BIT = 0;
DECLARE #ParentId INT
SELECT #ParentId = ParentId
FROM T
WHERE Id = #currentId
WHILE (#ParentId IS NOT NULL AND #Exists = 0)
BEGIN
IF EXISTS(SELECT * FROM T WHERE Id = #ParentId AND IsEnabled = 1)
BEGIN
SET #Exists = 1
END
ELSE
BEGIN
SELECT #ParentId = ParentId
FROM T
WHERE Id = #ParentId
END
IF (#Exists = 1 OR #ParentId IS NULL)
BEGIN
INSERT INTO #myTable
SELECT Id, ParentId, #ParentId
FROM T
WHERE Id = #currentId
END
END
FETCH NEXT FROM myCursor INTO #currentId;
END
CLOSE myCursor;
DEALLOCATE myCursor;
SELECT *
FROM #myTable
ORDER BY 1