MSSQLSERVER:
SELECT TT1.NO AS NO,MAX(TT1.HM) AS HM1,MAX(TT2.HM) AS HM2
FROM T1 TT1,T2 TT2
WHERE TT1.NO=TT2.NO AND TT1.HM<>TT2.HM
GROUP BY TT1.NO
HAVING COUNT(TT1.NO)=1
SELECT TT1.NO AS NO,MAX(TT1.HM) AS HM1,MAX(TT2.HM) AS HM2
FROM T1 TT1,T2 TT2
WHERE TT1.NO=TT2.NO AND TT1.HM<>TT2.HM
GROUP BY TT1.NO
HAVING COUNT(TT1.NO)=1
SELECT TT1.NO AS NO,MAX(TT1.HM) AS HM1,MAX(TT2.HM) AS HM2
FROM T1 TT1,T2 TT2
WHERE TT1.NO=TT2.NO AND TT1.HM<>TT2.HM
GROUP BY TT1.NO
HAVING COUNT(TT1.NO)=1
group by no, hm
having count(*) > 1