select case greatest(max(a),max(b),max(c),max(d)) when max(a) then 'a' when max(b) then 'b' when max(c) then 'c' when max(d) then 'd' end col_name, greatest(max(a),max(b),max(c),max(d)) from test_b;
큰 값 중복은 고려 안했을 경우는 작성해봅니다 ㅋ
row당이면
select case greatest(a,b,c,d) when a then 'a' when b then 'b' when c then 'c' when d then 'd' end col_name, greatest(a,b,c,d) from test_b;