How To Rollback the Current Transaction?

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