Oracle Database Interview Question:

How To Rollback the Current Transaction in Oracle?

Submitted by: Administrator

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/globalguideline

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

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

SQL> SELECT * FROM ggl_links;
ID URL NOTES COUNTS CREATED
------- ---------------- ---------- ---------- ---------
101 globalguideline.com 07-MAY-06
110 globalguideline.com/html 07-MAY-06
102 google.com 07-MAY-06
103 myspace.com 07-MAY-06</pre>
Submitted by: Administrator

SQL> ROLLBACK;
Rollback complete.

SQL> SELECT * FROM ggl_links;
<pre> ID URL NOTES COUNTS CREATED
------- ---------------- ---------- ---------- ---------
101 globalguideline.com 07-MAY-06
110 globalguideline.com/html 07-MAY-06</pre>
As you can see, the two new records inserted into the table were removed by the ROLLBACK statement.
Submitted by: Administrator