Oracle: Updating a table column using ROWNUM in conjunction with ORDER BY clause

Question

I want to populate a table column with a running integer number, so I\'m thinking of using ROWNUM. However, I need to populate it based on the order of other columns, someth

Answer 1

First Create a sequence :

CREATE SEQUENCE SEQ_SLNO
  START WITH 1
  MAXVALUE 999999999999999999999999999
  MINVALUE 1
  NOCYCLE
  NOCACHE
  NOORDER;

after that Update the table using the sequence:

UPDATE table_name
SET colun_name = SEQ_SLNO.NEXTVAL;