Select with a order by option

Question

Hi all,
I have this table
create table TEST_ORDI (
CODI_ORDI number(2),
NUME_AVVI VARCHAR2(6),
NUME_COLL VARCHAR2(6) )
where field COLL can be null or the reference of one value of AVVI.
For example, I've got those values
insert into test_ordi values (5,'C9998',NULL);
insert into test_ordi values (5,'C9999',NULL);
insert into test_ordi values (6,'C10000',NULL);
insert into test_ordi values (6,'C10001',NULL);
insert into test_ordi values (6,'C10002',NULL);
insert into test_ordi values (6,'C10003','C10000');
insert into test_ordi values (6,'C10004','C10000');
insert into test_ordi values (6,'C10005','C10000');
insert into test_ordi values (6,'C10007',NULL);
insert into test_ordi values (6,'C10008',NULL);
insert into test_ordi values (6,'C10009','C10000');
insert into test_ordi values (7,'C10010',NULL);
insert into test_ordi values (7,'C10011',NULL);
The problem is, that I must extract them like the result is, (where with "*" I've noticed the records that aren't in a order of field NUME_AVVI)
5,'C9998'
5,'C9999'
6,'C10001'
6,'C10002'
****6,'C10000'
6,'C10003','C10000'
6,'C10004','C10000'
6,'C10005','C10000'
****6,'C10009','C10000'
6,'C10007'
6,'C10008'
7,'C10010'
7,'C10011'
Notice that I must respect the NUME_ORDI like a first element of order by, and the NUME_AVVI like a second element of order by.
It's possible?
Thank's
Paolo from Madrid

Answer 1

Best I can come up with, assuming that your requirement is to keep rows with a nume_coll just below the row with the corresponding nume_avvi is:
select * from test_ordi
order by codi_ordi, nvl(nume_coll, nume_avvi), nume_avvi
CODI_ORDI     NUME_AVVI     NUME_COLL
5     C9998     
5     C9999     
6     C10000     
6     C10003     C10000
6     C10004     C10000
6     C10005     C10000
6     C10009     C10000
6     C10001     
6     C10002     
6     C10007     
6     C10008     
7     C10010     
7     C10011     It doesn't match your original order though, because as already mentioned, you haven't specified the rules for that particular order.