Auditing Table Data using Trigger

Create New User in Oracle

CREATE User <UserName> IDENTIFIED BY <Passsword>;

Grant User necessary privileges

GRANT CREATE session TO <username>;

GRANT CREATE TABLE TO <username>;

GRANT CREATE TRIGGER TO <username>;

ALTER USER <username> QUOTA UNLIMITED ON <TablespaceName>

Create a Transactional Table

CREATE TABLE AD_DURATIONS
  (
      Ad_Duration_Cn    Varchar2(10 Byte)     Not Null Enable,
      Ad_Start_Date     Date Not              Null Enable,
      Ad_End_Date       Date Not              Null Enable,
      Modified_By       Varchar2(10 Byte),
      Modified_Date     Date                  Default Sysdate,
      Constraint CJ_AD_DURATIONS_PK Primary Key (AD_DURATION_CN)
  );

Insert value in the AD_DURATIONS Table

Insert Into Ad_Durations (Ad_Duration_Cn, Ad_Start_Date,
                              Ad_End_Date, Modified_By)
Values ('10001', To_Date('26-JUL-10', 'DD-MON-RR'),
                              To_Date('30-JUL-10', 'DD-MON-RR'), 'Tamim');

Insert Into Ad_Durations (Ad_Duration_Cn, Ad_Start_Date,
                              Ad_End_Date, Modified_By)
Values ('10002', To_Date('31-JUL-10', 'DD-MON-RR'),
                              To_Date('05-Aug-10', 'DD-MON-RR'), 'Khan');

Create a Log Table for AD_DURATIONS Data

Here Modified_By, Modified_Date and Action is Audit Column.

CREATE TABLE AD_DURATIONS_LOG
  (
      Ad_Duration_Cn    Varchar2(10 Byte),
      Ad_Start_Date     Date,
      Ad_End_Date       Date,
      Modified_By       Varchar2(20 Byte),
      Modified_Date     Timestamp (6),
      Action            Varchar2(20 Byte)
  );

Create a Trigger on AD_DURATIONS table

Create Or Replace TRIGGER AD_DURATIONS_LOG
AFTER DELETE OR UPDATE ON AD_DURATIONS
FOR EACH ROW
Begin
  If Updating Then
      Insert Into Ad_Durations_Log(Ad_Duration_Cn, Ad_Start_Date,
                  Ad_End_Date, Modified_By,Modified_Date,Action)
      Values (:Old.Ad_Duration_Cn, :Old.Ad_Start_Date,:Old.Ad_End_Date,
                  :Old.Modified_By,:Old.Modified_Date,'Update');
  Elsif Deleting Then
      Insert Into Ad_Durations_Log(Ad_Duration_Cn, Ad_Start_Date,
                  Ad_End_Date, Modified_By,Modified_Date,Action)
      Values (:Old.Ad_Duration_Cn, :Old.Ad_Start_Date, :Old.Ad_End_Date,
                  :Old.Modified_By,:Old.Modified_Date,'Delete');
  End If;
END;

Update on AD_DURATIONS Table

Update Ad_Durations
Set Ad_End_Date = To_Date('31-JUL-10', 'DD-MON-RR')
Where Ad_Duration_Cn = 10001;

Update from AD_DURATIONS Table

Delete From Ad_Durations
Where Ad_Duration_Cn = 10002;

Now Selecting data from AD_DURATIONS_LOG Table.

Select * From Ad_Durations_Log;