Get all parents in parent child hierarchy - sql

Question

I have the following data in my table
ID NAME PARENTID STATUS
----------- ------------------------------ ----------- ------
1 Folder A 0 0
2 Folder B 1 0
3 Folder C 2 1
4 Folder D 1 0
5 Folder E 4 0
6 Folder G 5 0
7 Folder H 6 1
Above records are from table [#Temp].
[Name] - Folder Name
[ID] - Unique ID of folder in database (identity)
[ParentID] - Represents the parent of current folder.
Query to populate above data in the table:
DECLARE #Temp TABLE
(
[ID] INT IDENTITY(1, 1) ,
[NAME] VARCHAR(30) ,
[PARENTID] INT,
[STATUS] BIT
)
INSERT INTO #Temp
SELECT 'Folder A' ,
0, 0
UNION
SELECT 'Folder B' ,
1, 0
UNION
SELECT 'Folder C' ,
2, 1
UNION
SELECT 'Folder D' ,
1, 0
UNION
SELECT 'Folder E' ,
4, 0
UNION
SELECT 'Folder G' ,
5, 0
UNION
SELECT 'Folder H' ,
6, 1
I am having the following query to get records where status=1
SELECT *
FROM #Temp WHERE [STATUS]=1
which gives the following output
ID NAME PARENTID STATUS
----------- ------------------------------ ----------- ------
3 Folder C 2 1
7 Folder H 6 1
My goal is to fetch those records too which are the parents (till parentid=0) of the records came with the above query. i.e I want to get this output which contains the parents of Folder C and Folder H:
ID NAME PARENTID STATUS
----------- ------------------------------ ----------- ------
1 Folder A 0 0
2 Folder B 1 0
3 Folder C 2 1
4 Folder D 1 0
5 Folder E 4 0
6 Folder G 5 0
7 Folder H 6 1

Answer 1

DECLARE #Temp TABLE
(
[ID] INT IDENTITY(1, 1) ,
[NAME] VARCHAR(30) ,
[PARENTID] INT ,
[STATUS] BIT
)
INSERT INTO #Temp
SELECT 'Folder A' ,
0 ,
0
UNION
SELECT 'Folder B' ,
1 ,
0
UNION
SELECT 'Folder C' ,
2 ,
1
UNION
SELECT 'Folder D' ,
1 ,
0
UNION
SELECT 'Folder E' ,
4 ,
0
UNION
SELECT 'Folder G' ,
5 ,
1
UNION
SELECT 'Folder H' ,
6 ,
0
CREATE TABLE #TempTable
(
[RowIndex] INT IDENTITY(1, 1) ,
[ID] INT ,
[ParentID] INT
)
DECLARE #TempIds TABLE ( [ID] INT )
INSERT INTO #TempTable
( [ID] ,
[ParentID]
)
SELECT [ID] ,
[ParentID]
FROM #Temp
WHERE [STATUS] = 1
DECLARE #intFlag INT
DECLARE #Count INT
SET #intFlag = 1
SELECT #Count = COUNT(1)
FROM #Temp
WHILE ( #intFlag <= #Count )
BEGIN
PRINT #intFlag
DECLARE #ID INT
SELECT #ID = [ParentID]
FROM #TempTable
WHERE RowIndex = #intFlag
SET #intFlag = #intFlag + 1;
WITH CTE
AS ( SELECT ID ,
ParentID
FROM #Temp
WHERE ID = #ID
UNION ALL
SELECT MainTbl.ID ,
MainTbl.ParentID
FROM #Temp MainTbl
INNER JOIN cte ON MainTbl.ID = cte.ParentID
)
INSERT INTO #TempIds
SELECT ID
FROM CTE
END
;WITH cte
AS ( SELECT DISTINCT
ID
FROM #TempIds
)
SELECT T.*
FROM cte
INNER JOIN #Temp T ON [T].ID = cte.ID
UNION
SELECT T1.*
FROM #TempTable TempTable
INNER JOIN #Temp T1 ON [TempTable].ID = T1.ID
DROP TABLE #TempTable
Output:
ID NAME PARENTID STATUS
----------- ------------------------------ ----------- ------
1 Folder A 0 0
2 Folder B 1 0
3 Folder C 2 1
4 Folder D 1 0
5 Folder E 4 0
6 Folder G 5 1

Answer 2

I made a recursive CTE - I start with the bottom, any folder that does not have a child. From there, I pass up whether or not a '1' Status was encountered in the 'GOOD' column, and the distinct clears out the duplicates created by starting at the bottom.
;WITH CTE AS
(
SELECT ID, NAME, PARENTID, STATUS GOOD, STATUS
FROM #Temp T1
WHERE NOT EXISTS (SELECT * FROM #Temp T2 WHERE T2.PARENTID = T1.ID)
UNION ALL
SELECT T.ID, T.NAME, T.PARENTID, T.STATUS | C.GOOD GOOD, T.STATUS
FROM #Temp T
JOIN CTE C
ON C.PARENTID = T.ID
)
SELECT DISTINCT ID, NAME, PARENTID, STATUS FROM CTE
WHERE GOOD = 1
ORDER BY ID ASC