How To Rollback the Current Transaction? - Oracle DBA FAQ - Understanding SQL Transaction Management

If you have used some DML statements updated some data objects, you find a problem with those updates, and you don't want those updates to be permanently recorded in the database, you can use the ROLLBACK statement. It will remove all the database changes made in the current transaction and end the current transaction. The following tutorial exercise shows you how to use ROLLBACK statements:

SQL> connect HR/fyicenter

SQL> INSERT INTO fyi_links (url, id) 
  2  VALUES ('google.com', 102);

SQL> INSERT INTO fyi_links (url, id) 
  3  VALUES ('myspace.com', 103);

SQL> SELECT * FROM fyi_links;
     ID URL              NOTES          COUNTS CREATED
------- ---------------- ---------- ---------- ---------
    101 fyicenter.com                          07-MAY-06
    110 centerfyi.com                          07-MAY-06
    102 google.com                             07-MAY-06
    103 myspace.com                            07-MAY-06

SQL> ROLLBACK;
Rollback complete.

SQL> SELECT * FROM fyi_links;
     ID URL              NOTES          COUNTS CREATED
------- ---------------- ---------- ---------- ---------
    101 fyicenter.com                          07-MAY-06
    110 centerfyi.com                          07-MAY-06

As you can see, the two new records inserted into the table were removed by the ROLLBACK statement.