Need help on the update statement

Question

Hi,
I have a small requirement. I have a table called test1 and it has 2 columns, nam and seq. nam is a VARCHAR2(100) and seq is a NUMBER.
In the seq I have values like, 2, 3, 7, 9, 25. I would like to update the seq value in an order such that it will be modifed like, 1, 2, 3, 4 and 5.
Here is the scripts, I have used.
CREATE TABLE test1
(nam VARCHAR2(100),
  seq NUMBER);
INSERT INTO test1 VALUES('AAA', 2);
INSERT INTO test1 VALUES('BBB', 3);
INSERT INTO test1 VALUES('CCC', 7);
INSERT INTO test1 VALUES('DDD', 9);
INSERT INTO test1 VALUES('EEE', 25);
COMMIT;
And, I would like to achive this in a simple single DML statement. (The required output would be something like, AAA - 1, BBB - 2 etc,...)
I have tried the following query. It is working fine. But If I have a better solution to it, I would to implement the same.
UPDATE test1 a
  SET seq =
  (SELECT rn
  FROM (SELECT ROW_NUMBER() OVER(ORDER BY seq) rn FROM test1) x
  WHERE a.rowid = x.rowid);
PS: I am using Oracle 11.2.0.2.0 (11g)
Thanks In Advance!
With Regards,
VST

Answer 1

SQL> CREATE TABLE test1 
  2   (nam VARCHAR2(100), 
  3    seq NUMBER); 
Table created.
SQL>  INSERT INTO test1 VALUES('AAA', 2); 
1 row created.
SQL>  INSERT INTO test1 VALUES('BBB', 3); 
1 row created.
SQL>  INSERT INTO test1 VALUES('CCC', 7); 
1 row created.
SQL>  INSERT INTO test1 VALUES('DDD', 9); 
1 row created.
SQL>  INSERT INTO test1 VALUES('EEE', 25); 
1 row created.
SQL>  COMMIT; 
Commit complete.
SQL> select * from test1;
NAM                                                                                                         SEQ
AAA                                                                                                           2
BBB                                                                                                           3
CCC                                                                                                           7
DDD                                                                                                           9
EEE                                                                                                          25
5 rows selected.
SQL> update test1 set seq = rownum;
5 rows updated.
SQL> select * from test1;
NAM                                                                                                         SEQ
AAA                                                                                                           1
BBB                                                                                                           2
CCC                                                                                                           3
DDD                                                                                                           4
EEE                                                                                                           5
5 rows selected.