Mega Code Archive

 

Categories / Oracle PLSQL / Trigger

 

Templace for using trigger as a log method

SQL> -- create demo table SQL> create table Employee(   2    ID                 VARCHAR2(4 BYTE)         NOT NULL,   3    First_Name         VARCHAR2(10 BYTE),   4    Last_Name          VARCHAR2(10 BYTE),   5    Start_Date         DATE,   6    End_Date           DATE,   7    Salary             Number(8,2),   8    City               VARCHAR2(10 BYTE),   9    Description        VARCHAR2(15 BYTE)  10  )  11  / SQL> SQL> -- prepare data SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2               values ('01','Jason',    'Martin',  to_date('19960725','YYYYMMDD'), to_date('20060725','YYYYMMDD'), 1234.56, 'Toronto',  'Programmer')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('02','Alison',   'Mathews', to_date('19760321','YYYYMMDD'), to_date('19860221','YYYYMMDD'), 6661.78, 'Vancouver','Tester')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('03','James',    'Smith',   to_date('19781212','YYYYMMDD'), to_date('19900315','YYYYMMDD'), 6544.78, 'Vancouver','Tester')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('04','Celia',    'Rice',    to_date('19821024','YYYYMMDD'), to_date('19990421','YYYYMMDD'), 2344.78, 'Vancouver','Manager')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('05','Robert',   'Black',   to_date('19840115','YYYYMMDD'), to_date('19980808','YYYYMMDD'), 2334.78, 'Vancouver','Tester')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('06','Linda',    'Green',   to_date('19870730','YYYYMMDD'), to_date('19960104','YYYYMMDD'), 4322.78,'New York',  'Tester')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('07','David',    'Larry',   to_date('19901231','YYYYMMDD'), to_date('19980212','YYYYMMDD'), 7897.78,'New York',  'Manager')   3  / SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('08','James',    'Cat',     to_date('19960917','YYYYMMDD'), to_date('20020415','YYYYMMDD'), 1232.78,'Vancouver', 'Tester')   3  / SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee   2  / ID   FIRST_NAME LAST_NAME  START_DAT END_DATE      SALARY CITY       DESCRIPTION ---- ---------- ---------- --------- --------- ---------- ---------- --------------- 01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer 02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester 03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester 04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver  Manager 05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester 06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York   Tester 07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York   Manager 08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver  Tester SQL> SQL> SQL> SQL> create table employees_copy as select * from employee; SQL> SQL> create table employees_log(who varchar2(10),   2                             action varchar2(10),   3                             when date ); SQL> SQL> SQL> SQL> SQL> desc employees_log  Name                                                                                                  Null?    Type  ----------------------------------------------------------------------------------------------------- -------- --------------------------------------------------------------------  WHO                                                                                                    VARCHAR2(10)  ACTION                                                                                                 VARCHAR2(10)  WHEN                                                                                                   DATE SQL> SQL> create or replace trigger biud_employees_copy   2    before insert or update or delete   3       on employees_copy   4  declare   5    l_action employees_log.action%type;   6  begin   7    if INSERTING then   8      l_action := 'Insert';   9    elsif UPDATING then  10      l_action := 'Update';  11    elsif DELETING then  12      l_action := 'Delete';  13    else  14      raise_application_error( -20001,  15          'You should never ever get this error.' );  16    end if;  17  18    insert into employees_log(  19      who, action, when )  20    values(  21      user, l_action, sysdate );  22  end;  23  / SQL> SQL> insert into employees_copy(id,last_name,Start_date)  values   2                            ( 1234,'Beck', sysdate); SQL> SQL> select * from employees_log; WHO        ACTION     WHEN ---------- ---------- --------- RNTSOFT     Insert     09-SEP-06 SQL> SQL> update employees_copy   2    set salary = 500000.00; SQL> SQL> select * from employees_log; WHO        ACTION     WHEN ---------- ---------- --------- RNTSOFT     Insert     09-SEP-06 RNTSOFT     Update     09-SEP-06 SQL> SQL> drop table employees_log; SQL> SQL> drop table employees_copy; SQL> SQL> SQL> -- clean the table SQL> drop table Employee   2  / SQL> SQL>