Join issue

Question

I have two tables a and b ...the data in the two tables are as follow
TABLE a
a_date flag
29-SEP-2008 Y
28-SEP-2008
27-SEP-2008
26-SEP-2008 Y
25-SEP-2008
TABLE b
b_date
29-SEP-2008
now when a_date=b_date then i need to select the data from that date to the previous record from the next suceesive flag in table a i.e, my output should show
29-SEP-2008 Y
28-SEP-2008
27-SEP-2008
the flag can occur anywhere in the data so there is no use of using rownum.Please help with a solution

Answer 1

What about this ->
satyaki>
satyaki>select * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - Prod
PL/SQL Release 10.2.0.3.0 - Production
CORE    10.2.0.3.0      Production
TNS for 32-bit Windows: Version 10.2.0.3.0 - Production
NLSRTL Version 10.2.0.3.0 - Production
Elapsed: 00:00:00.47
satyaki>
satyaki>--Start Test Data Segment
satyaki>with a
  2  as
  3    (
  4       select to_date('29-SEP-2008','DD-MON-YYYY') a_date, 'Y' flag from dual
  5       union all
  6       select to_date('28-SEP-2008','DD-MON-YYYY'), null from dual
  7       union all
  8       select to_date('27-SEP-2008','DD-MON-YYYY'), null from dual
  9       union all
10       select to_date('26-SEP-2008','DD-MON-YYYY'), 'Y' from dual
11       union all
12       select to_date('25-SEP-2008','DD-MON-YYYY'), null from dual
13    ),
14    b
15  as
16    (
17       select to_date('29-SEP-2008','DD-MON-YYYY') b_date from dual
18    )
19  --End Of Test Data Segment
20  select a.a_date,
21         case
22           when a.a_date = b.b_date then
23             'Y'
24         else
25           null
26         end flag
27  from a, b
28  where a.a_date = b.b_date(+)
29  order by a.a_date desc;
A_DATE    F
29-SEP-08 Y
28-SEP-08
27-SEP-08
26-SEP-08
25-SEP-08
Elapsed: 00:00:00.92Regards.
Satyaki De.