With Test As (
 Select '001' no, '20120401' exe_Date, '' a, '80' b, '40' c, '74' d From Dual Union All
 Select '001' no, '20120405' exe_Date, '61' a, '90' b, '50' c, '' d From Dual Union All
 Select '002' no, '20120401' exe_Date, '90' a, '' b, '50' c, '' d From Dual Union All
 Select '002' no, '20120411' exe_Date, '85' a, '70' b, '60' c, '' d From Dual
)
Select * From Test;

원본 데이터) 일자별 취득학점
NO EXE_DATE A B C D
-------------------------------------
001 20120401     80 40 74
001 20120405 61 90 50 
002 20120401 90     50 
002 20120411 85 70 60 

원하는 결과) 개인별 최초 취득학점
NO   A  B  C  D
-------------------------
001  61 80 40 74
002  90 70 50