Query help needed in finding max value between two columns

Question

I have a table as follows:
-- INSERTING into TESTTABLE
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('A','4.5','AA',0.3,'AB',5.5);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('B','1','BB',2.5,'BC',6.9);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('C','2.6','CC',3.3,'CD',1.4);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('D','1.8','DD',2.9,'DE',1.2);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('E','6.8','EE',4.8,'EF',9.6);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('F','2.0','FF',6.34,'FG',3.9);
Insert into TESTTABLE (COLA,COL2,COLC,COLD,COLE,COLF) values ('G','1.7','GG',3.6,'GH',5.8);
I want to get results as follows:
COLA COL2 MaxCol MaxColVal
A 4.5 AB 5.5
B 1 BC 6.9
C 2.6 CC 3.3
D 1.8 DD 2.9
E 6.8 EF 9.6
F 2.0 FF 6.34
G 1.7 GH  5.8I want to get the max value of either of the columns COLD or COLF.. Whichever column has got max value, then the corresponding value of COLC and COLE should be returned..
For eg., in first row, COLF has higher value than COLD.. ie., COLF = 5.5 > COLD = 0.3, so for row1, i want the result as MaxCol is AB and MaxColvalue is 5.5..
Similarly for third row, COLD =3.3 > COLF=1.4, so for 3rd row, i want the result as MaxCol is CC and MaxColvalue is 3.3
How is it possible to do this in a qery? Any help.. please..

Answer 1

SQL> select cola
  2       , col2
  3       , case greatest(cold,colf)
  4         when cold then colc
  5         else cole
  6         end maxcol
  7       , greatest(cold,colf) maxcolval
  8    from testtable
  9  /
C COL MA  MAXCOLVAL
A 4.5 AB        5,5
B 1   BC        6,9
C 2.6 CC        3,3
D 1.8 DD        2,9
E 6.8 EF        9,6
F 2.0 FF       6,34
G 1.7 GH        5,8
7 rijen zijn geselecteerd.Regards,
Rob.