SQL & PL/SQL :: Creating Oracle Query To Fetch Information Using PIVOT Option?

creating Oracle SQL query to fetch the information using PIVOT option.We are populating audit table using triggers. For every update, there will be two rows into audit table, one row with all OLD values and another with all NEW values. Also every updated is uniquely identified by Sequence No. Example for phone audit is mentioned below :

CREATE TABLE test_audit_phone
(
emplid VARCHAR2(10),
seqno NUMBER,
action VARCHAR2(3),
office NUMBER,
mobile NUMBER
);

Insert some rows into table.

INSERT INTO test_audit_phone VALUES ('100',1,'OLD',1111,9999)
/
INSERT INTO test_audit_phone VALUES ('100',1,'NEW',2222,9999)
/
INSERT INTO test_audit_phone VALUES ('100',2,'OLD',2222,9999)
/
INSERT INTO test_audit_phone VALUES ('100',2,'NEW',2222,8888)
/

Table will look like the following :

SQL> SELECT * FROM sysadm.test_audit_phone ;

EMPLID SEQNO ACT OFFICE MOBILE
---------- ---------- --- ---------- ----------
100 1 OLD 1111 9999
100 1 NEW 2222 9999
100 2 OLD 2222 9999
100 2 NEW 2222 8888

Now we have to present data in different format. For each field, display OLD and NEW values in column format.

EMPLIDFIELDOLDNEW
----- ------ ---- -----
100OFFICE11112222
100MOBILE99998888

Challenges :

1) Make pivoting with old and new values

2) For each field we have to show old and new values

3)if old and new values are same, dont show in report.