Column to row conversion

Question

I would like to convert rows to columns of a sql.
select col1, col2, col3, col4
ABC 1 2 3
DEF 4 5 6
GHI 7 8 9
I want to convert to
ABC DEF GHI
1 4 7
2 5 8
3 6 9
Thanks for your response.

Answer 1

select regexp_substr( col1,'[^\,]+',1,1) column1,
       regexp_substr( col1,'[^\,]+',1,2) column2,
       regexp_substr( col1,'[^\,]+',1,3) column3
from (
WITH t AS
(select 'ABC' col1,  1 col2, 2 col3, 3 col4 from dual union
select 'DEF', 4, 5, 6 from dual union
select   'GHI', 7, 8, 9 from dual
SELECT  substr(SYS_CONNECT_BY_PATH (col1, ' ,'),2) col1
FROM (SELECT col1,
ROW_NUMBER () OVER ( ORDER BY COl1) rn
FROM t)
WHERE connect_by_isleaf = 1
START WITH rn = 1
CONNECT BY PRIOR rn = rn - 1
union all
SELECT  substr(SYS_CONNECT_BY_PATH (col2, ' ,'),2) col2
FROM (SELECT col2,
ROW_NUMBER () OVER ( ORDER BY COl2) rn
FROM t)
WHERE connect_by_isleaf = 1
START WITH rn = 1
CONNECT BY PRIOR rn = rn - 1
union all
SELECT  substr(SYS_CONNECT_BY_PATH (col3, ' ,'),2) col3
FROM (SELECT col3,
ROW_NUMBER () OVER ( ORDER BY COl3) rn
FROM t)
WHERE connect_by_isleaf = 1
START WITH rn = 1
CONNECT BY PRIOR rn = rn - 1
union all
SELECT  substr(SYS_CONNECT_BY_PATH (col4, ' ,'),2) col4
FROM (SELECT col4,
ROW_NUMBER () OVER ( ORDER BY COl4) rn
FROM t)
WHERE connect_by_isleaf = 1
START WITH rn = 1
CONNECT BY PRIOR rn = rn - 1
) t1