;with Table1
AS
	(SELECT 'cltstyle, InvNbr, PoNbr' AS indexColumn)
,Table2
AS
	(SELECT 1 AS indexid, 'cltstyle' AS ColumnName UNION ALL
	SELECT 2, 'id' UNION ALL
	SELECT 3, 'Tab9' UNION ALL
	SELECT 4, 'cltstyle' UNION ALL
	SELECT 4, 'InvNbr' UNION ALL
	SELECT 4, 'PoNbr' UNION ALL
	SELECT 5, 'InvNbr' UNION ALL
	SELECT 6, 'ID' UNION ALL
	SELECT 6, 'PoNbr' UNION ALL
	SELECT 6, 'InvNbr'UNION ALL
	SELECT 4, 'PoNbr' )

, TableR
AS
(
	SELECT
	  indexid
	  ,ColumnName
	  ,ROW_NUMBER() OVER(PARTITION BY indexid , ColumnName ORDER BY indexid,ColumnName) AS RN
	  ,CASE WHEN CHARINDEX (ColumnName,indexColumn,0)>0 THEN 1   --columnName 'cltstyle' in  indexColumn 'cltstyle, InvNbr, PoNbr'
			ELSE 0 END AS Positions
	  ,LEN(indexColumn) - LEN(REPLACE(indexColumn,',','')) + 1 AS NoOfColumns --Numbers of columns from indexColumn
	FROM 
		Table2
		CROSS JOIN Table1
)

, TableB
AS
(
	SELECT
	A.indexid
	,A.ColumnName		
	,SUM(A.Positions) OVER(PARTITION BY indexid ORDER BY indexid,ColumnName ) AS X
	,NoOfColumns
	FROM
		TableR AS A
	WHERE A.RN = 1
		AND A.Positions = 1
)

SELECT
	indexID
	,ColumnName
FROM
	TableB as B
WHERE 
	B.indexID IN (select indexID FROM TableB GROUP BY indexID,NoOfColumns HAVING MAX(x)=NoOfColumns)
	
	

indexID	ColumnName
4	cltstyle
4	InvNbr
4	PoNbr

;with TableSplit
AS
(	SELECT
		iIndex
		,REPLACE(splitData,' ','') AS ColumnName
	FROM 
	Table1
	CROSS APPLY dbo.fnSplitString(indexColumn,',') )
,
TableResult
AS
(
	SELECT
		A.indexID
		,A.ColumnName
		,S.iIndex	
		,ROW_NUMBER() OVER (PARTITION BY A.indexID,A.ColumnName Order by A.indexID,A.ColumnName) AS RN	
		,DENSE_RANK() OVER (PARTITION BY A.indexID Order by A.indexID,A.ColumnName) AS Dk
	FROM
		Table2 AS A
		LEFT JOIN TableSplit AS S
		ON A.ColumnName = S.ColumnName	
)


SELECT 
	indexID
	,ColumnName 
FROM TableResult
WHERE
	1=1
	--AND indexID NOT IN (SELECT indexID FROM TableResult WHERE iIndex IS NULL)
	AND indexID IN (SELECT indexID FROM TableResult GROUP BY indexID HAVING MAX(iIndex) = (SELECT MAX(iIndex) FROM TableSplit))
	AND iIndex  = Dk
	AND RN = 1