Help with select/update?

Question

Basically I want to have table to behave like the "netflix" movie queue priority where a user can update a row ( or any number of rows) in the queue to be any priority and the queue sorts out the new order of the queue.
Can this be done with a select?
Say I have a table with 3 columns Such as:
prio     new_prio     name
1     1          First record
2     2          Second record
3     3          Third Record
4     4          Forth Record
5     5          Fifth Record
6     6          Sixth RecordWhat I want to happen is that the prio, to always be sequence, starting at 1, incrementing for each record for the whole table.
So if I took the same table and updated the new_prio as follows:
prio     new_prio     name
1     1          First record
2     2          Second record
3     2          Third Record  <- updated this record  new_prio = 2
4     4          Forth Record
5     3          Fifth Record  <- updated this record  new_prio = 3
6     6          Sixth RecordI would want to update the prio column to follow the updates from the new_prio column So the results would look like (sorted on prio):
prio     new_prio     name
1     1          First record
2     2          Third Record
3     3          Fifth Record
4     4          Second record
5     5          Forth Record
6     6          Sixth RecordNow say I delete the two records like:
prio     new_prio     name
1     1          First record
2     2          Third Record  <- delete this one
3     3          Fifth Record  <- and this one
4     4          Second record
5     5          Forth Record
6     6          Sixth RecordI would expect the following:
prio     new_prio     name
1     1          First record
2     2          Second record
3     3          Forth Record
4     4          Sixth RecordIs there a way to get this done in a simple select or update? what about a simple cursor loop?
I know I could do this with a lot of pl/sql code, But I am very interested if this could be done in sql. I have come close with using a cursor loop with inline views using rownum, but I am hitting problems with moving more then 2 rows around. when updating multiple rows, some rows come out one or two rows out of their intended order/prio.
Thanks in advance.
--pat                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Answer 1

SQL> create table netflix
  2  as
  3  select 1 o, 1 n, 'ONE' t from dual union all
  4  select 2, 2, 'TWO' from dual union all
  5  select 3, 9, 'THREE' from dual union all
  6  select 4, 10, 'FOUR' from dual union all
  7  select 5, 5, 'FIVE' from dual union all
  8  select 6, 6, 'SIX' from dual union all
  9  select 7, 7, 'SEVEN' from dual union all
10  select 8, 1, 'EIGHT' from dual union all
11  select 9, 2, 'NINE' from dual union all
12  select 10, 3, 'TEN' from dual union all
13  select 11, 11, 'ELEVEN' from dual
14  /
Tabel is aangemaakt.
SQL> SELECT o, n, t
  2    from netflix
  3  /
         O          N T
         1          1 ONE
         2          2 TWO
         3          9 THREE
         4         10 FOUR
         5          5 FIVE
         6          6 SIX
         7          7 SEVEN
         8          1 EIGHT
         9          2 NINE
        10          3 TEN
        11         11 ELEVEN
11 rijen zijn geselecteerd.
SQL> select i, t
  2    from dual
  3   model
  4         reference changed_numbers on
  5           ( select n, t
  6               from netflix
  7              where o <> n
  8           )
  9           dimension by (n)
10           measures (t)
11         reference unchanged_numbers on
12           ( select row_number() over (order by n) n
13                  , t
14               from netflix
15              where o = n
16           )
17           dimension by (n)
18           measures (t)
19         main m
20         dimension by (1 i)
21         measures (cast(null as varchar2(10)) t, 1 last_n)
22         rules iterate (1000)
23               until (   unchanged_numbers.t[last_n[1]] is null
24                     and changed_numbers.t[iteration_number+1] is null
25                     )
26         ( t[iteration_number+1]
27           = nvl
28             ( changed_numbers.t[iteration_number+1]
29             , unchanged_numbers.t[last_n[1]]
30             )
31         , last_n[1] = last_n[1] + nvl2(changed_numbers.t[iteration_number+1],0,1)
32         )
33  /
         I T
         1 EIGHT
         2 NINE
         3 TEN
         4 ONE
         5 TWO
         6 FIVE
         7 SIX
         8 SEVEN
         9 THREE
        10 FOUR
        11 ELEVEN
11 rijen zijn geselecteerd.Regards,
Rob.