[Sql] 행을 열로 표시

select 

regexp_substr(a1, '[^,]+', 1, level) as a1 

from ( 

select 

a1 || ',' || b1 || ',' || c1 as a1 

from ( 

select 

 'aa1' as a1 

, 'aa2' as b1 

, 'aa3' as c1 

from dual 

) 

) 

connect by regexp_substr(a1, '[^,]+', 1, level) is not null