SQL & PL/SQL

Hello,

i have a table test contains these data.

group sequence value
1 1 100
1 2 200
1 3 300
1 4 400
1 5 500
1 6 600


Now i want to change the sequence. ie, eg change the sequence of 2nd record to 5th.
ie moving the 2nd record to 5th and re arrange the sequence. so the records get rearranged
with new sequence.


3 becomes ==> 2
4 becomes ==> 3
5 becomes ==> 4


so the records should looks like

1 1 100
1 2 300
1 3 400
1 4 500
1 5 200 --> 2nd record moved to 5th
1 6 600


how can i achieve this?