Sqlquery

Question

Hi,
I want to delete duplicate records and display remaining records in a table using single sql statement. Is it possible.
can any one let me know?
Thanks,
Rajesh

Answer 1

drop table test;
create table test(id number);
insert into test values(1);
insert into test values(1);
insert into test values(2);
commit;
create or replace function dont_use return number
is
pragma autonomous_transaction;
n number;
begin
delete from test t
where rowid not in ( select max(rowid) from test group by id);
n := sql%rowcount;
commit;
return n;
end;
select *
from test;
ID
1
1
2
--"The below SINGLE SQL will delete dups and will show the unique values
with dont_use_t as
select /*+ materialize */ dont_use cnt
from dual
select *
from test t,dont_use_t
where t.rowid in ( select max(rowid) from test group by id);
ID      CNT
2     1
1     1
select *
from test;
ID
2
1
{code}
Hypothetical answer for a hypothetical question.. :)
Edited by: jeneesh on Mar 1, 2013 3:47 PM