Help with the SQL Query: How to use case.

Question

Q:- I have written a query which will written the following output.
C1 C2 C3
a ---- b.1 ---- 1
a ---- b.1 ---- 1
a ---- b.1 ---- 2
a ---- b.1 ---- 3
a ---- b.1 ---- 3
a ---- b.2 ---- 1
a ---- b.2 ---- 2
a ---- b.2 ---- 2
a ---- b.3 ---- 1
ac---- b.1 ---- 1
ac---- b.1 ---- 2
ac---- b.2 ---- 1
ac---- b.2 ---- 2
ac---- b.2 ---- 3
ac---- b.2 ---- 3
ac---- b ---- 1
But i want the output to print in the following way. Please suggest.
C1 C2 C3
a ---- b.1 ---- 1
------------------2
------------------3
a ---- b.2 ---- 1
------------------2
a ---- b.3 ---- 1
ac---- b.1 ---- 1
------------------2
ac---- b.2 ---- 1
------------------2
ac---- b.2 ---- 3
ac---- b ---- 1
Edited by: user555994 on Jan 18, 2011 1:42 AM
Edited by: user555994 on Jan 18, 2011 1:43 AM

Answer 1

Or may be
SQL> ed
Wrote file afiedt.buf
  1  WITH sample_data AS
  2    (SELECT 'a' C1,'b.1' C2, 1 C3 FROM dual UNION ALL
  3     SELECT 'a' C1,'b.1' C2, 1 C3 FROM dual UNION ALL
  4     SELECT 'a' C1,'b.1' C2, 2 C3 FROM dual UNION ALL
  5     SELECT 'a' C1,'b.1' C2, 3 C3 FROM dual UNION ALL
  6     SELECT 'a' C1,'b.1' C2, 3 C3 FROM dual UNION ALL
  7     SELECT 'a' C1,'b.2' C2, 1 C3 FROM dual UNION ALL
  8     SELECT 'a' C1,'b.2' C2, 2 C3 FROM dual UNION ALL
  9     SELECT 'a' C1,'b.2' C2, 2 C3 FROM dual UNION ALL
10     SELECT 'a' C1,'b.3' C2, 1 C3 FROM dual UNION ALL
11     SELECT 'ac' C1,'b.1' C2, 1 C3 FROM dual UNION ALL
12     SELECT 'ac' C1,'b.1' C2, 2 C3 FROM dual UNION ALL
13     SELECT 'ac' C1,'b.2' C2, 1 C3 FROM dual UNION ALL
14     SELECT 'ac' C1,'b.2' C2, 2 C3 FROM dual UNION ALL
15     SELECT 'ac' C1,'b.2' C2, 3 C3 FROM dual UNION ALL
16     SELECT 'ac' C1,'b.2' C2, 3 C3 FROM dual UNION ALL
17     SELECT 'ac' C1,'b' C2, 1 C3 FROM dual
18     )
19  SELECT
20         NVL2(LAG(C1) OVER (PARTITION BY C1,C2 ORDER BY C1,C2,C3),NULL,C1) C1
21        ,NVL2(LAG(C2) OVER (PARTITION BY C1,C2 ORDER BY C1,C2,C3),NULL,C2) C2
22        ,C3
23* FROM (SELECT DISTINCT c1,c2,c3 FROM sample_data)
SQL> /
C1 C2          C3
a  b.1          1
                2
                3
a  b.2          1
                2
a  b.3          1
ac b            1
ac b.1          1
                2
ac b.2          1
                2
C1 C2          C3
                3
12 rows selected.
SQL>