CREATE TABLE Parent (
	PntKey	int,
	PntQty	int)
	
CREATE TABLE Child1 (
	Cd1Key		int,
	Cd1PntKey	int,
	Cd1FromDate	date,
	Cd1ToDate	date)
	
CREATE TABLE Child2 (
	Cd2Key		int,
	Cd2PntKey	int,
	Cd2FromDate	date,
	Cd2ToDate	date)
	
INSERT INTO Parent (PntKey, PntQty)
SELECT	1, 100
UNION ALL SELECT 2, 200
UNION ALL SELECT 3, 300

INSERT INTO Child1 (Cd1Key, Cd1PntKey, Cd1FromDate, Cd1ToDate)
SELECT 1,1,'1-1-2012','2-1-2012'
UNION ALL SELECT 2,1,'4-1-2012','5-1-2012'
UNION ALL SELECT 3,2,'1-15-2012','5-15-2012'
UNION ALL SELECT 4,3,'5-1-2012','7-1-2012'

INSERT INTO Child2 (Cd2Key, Cd2PntKey, Cd2FromDate, Cd2ToDate)
SELECT 1,1,'12-1-2011','12-31-2011'
UNION ALL SELECT 2,2,'1-1-2012','2-1-2012'
UNION ALL SELECT 3,2,'2-15-2012','5-15-2012'
UNION ALL SELECT 4,3,'9-1-2012','10-1-2012'

SELECT	PntKey,
		Qty,
		FromDate1,
		ToDate1,
		FromDate2,
		ToDate2
FROM (
	SELECT	PntKey	PntKey, 
			PntQty	Qty,
			NULL	FromDate1,
			NULL	ToDate1,
			NULL	FromDate2,
			NULL	ToDate2 
	FROM	Parent
	UNION ALL
	SELECT	Cd1PntKey	PntKey,
			NULL		Qty,
			Cd1FromDate	FromDate1,
			Cd1ToDate	ToDate1,
			NULL		FromDate2,
			NULL		ToDate2
	FROM	Child1
	UNION ALL
	SELECT	Cd2PntKey	PntKey,
			NULL		Qty,
			NULL		FromDate1,
			NULL		ToDate1,
			Cd2FromDate	FromDate2,
			Cd2ToDate	ToDate2
	FROM	Child2
) AS WORK

ORDER BY PntKey, Qty desc

select PntKey,
		#Parent.PntQty Qty,
		#Child1.Cd1FromDate FromDate1,
		#Child1.Cd1ToDate ToDate1,
		#Child2.Cd2FromDate FromDate2,
		#Child2.Cd2ToDate ToDate2
FROM #Parent
LEFT JOIN #Child1 ON #Child1.Cd1PntKey = #Parent.PntKey
LEFT JOIN #Child2 ON #Child2.Cd2PntKey = #Parent.PntKey

select	PntKey,
		RowNumber,
		CASE
			WHEN RowNumber = 1 THEN Qty
			ELSE 0
		END					Qty,
		min(FromDate1),
		max(ToDate1),
		min(FromDate2),
		max(ToDate2)
from

(
	select	PntKey,
			ROW_NUMBER() OVER(PARTITION BY PntKey ORDER BY PntKey) AS 'RowNumber',
			Parent.PntQty Qty,
			Child1.Cd1FromDate FromDate1,
			Child1.Cd1ToDate ToDate1,
			null FromDate2,
			null ToDate2
	FROM Parent
	LEFT JOIN Child1 ON Child1.Cd1PntKey = Parent.PntKey

	union
	select  PntKey,
			ROW_NUMBER() OVER(PARTITION BY PntKey ORDER BY PntKey) AS 'RowNumber',
			Parent.PntQty Qty,
			null FromDate1,
			null ToDate1,
			Child2.Cd2FromDate FromDate2,
			Child2.Cd2ToDate ToDate2
	FROM Parent
	LEFT JOIN Child2 ON Child2.Cd2PntKey = Parent.PntKey
) as work
group by PntKey,
		RowNumber,
		CASE
			WHEN RowNumber = 1 THEN Qty
			ELSE 0
		END

SELECT PntKey=ISNULL(PntKey, Cd2PntKey)
    ,PntQty=CASE WHEN n1 = 1 THEN PntQty END
    ,FromDate1, ToDate1
    ,FromDate2=Cd2FromDate, ToDate2=Cd2ToDate
FROM ( 
    SELECT p.PntKey
        ,p.PntQty
        ,FromDate1=Cd1FromDate
        ,ToDate1=Cd1ToDate
        ,n1=ROW_NUMBER() OVER (PARTITION BY PntKey ORDER BY Cd1Key)
    FROM #Parent p
    RIGHT JOIN #Child1 c1 ON p.PntKey = c1.Cd1PntKey) a
FULL JOIN (
    SELECT Cd2Key, Cd2PntKey, Cd2FromDate, Cd2ToDate
        ,n2=ROW_NUMBER() OVER (PARTITION BY Cd2PntKey ORDER BY Cd2Key)
    FROM #Child2) c2
    ON a.PntKey = c2.Cd2PntKey AND a.n1 = c2.n2  
ORDER BY PntKey