Oracle PL/SQL/Trigger/Triggerable Actions

Check user name in a trigger

 
SQL>
SQL>
SQL> create table foo( a number );
Table created.
SQL>
SQL> create or replace trigger biud_foo
  2    before insert or update or delete
  3       on foo
  4  begin
  5    if user not in ( "CLBECK", "SDILLON" ) then raise_application_error( -20001,"You do not have access to modify this table." );
  6    end if;
  7  end;
  8  /
Trigger created.
SQL>
SQL> insert into foo (a) VALUES (1);
insert into foo (a) VALUES (1)
            *
ERROR at line 1:
ORA-20001: You do not have access to modify this table.
ORA-06512: at "sqle.BIUD_FOO", line 2
ORA-04088: error during execution of trigger "sqle.BIUD_FOO"

SQL>
SQL> drop table foo;
Table dropped.
SQL>

Log all triggerable action: iinsert, update and delete to a log table

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(
  2    who      varchar2(30),
  3    action   varchar2(100),
  4    when     date );
SQL>
SQL>
SQL> create or replace trigger biud_employees_copy
  2    before insert or update or delete
  3       on employees_copy
  4  begin
  5    state_package.rows_changed := 0;
  6  end;
  7  /
SQL>
SQL> create trigger biudfer_employees_copy
  2    before insert or update or delete
  3       on employees_copy
  4    for each row
  5  declare
  6    l_action employees_log.action%type;
  7  begin
  8    if INSERTING then
  9      l_action := "Insert";
 10    elsif UPDATING then
 11      l_action := "Update";
 12    elsif DELETING then
 13      l_action := "Delete";
 14    else
 15      raise_application_error( -20001,
 16        "You should never ever get this error." );
 17    end if;
 18
 19    state_package.rows_changed := state_package.rows_changed + 1;
 20
 21    if UPDATING( "SALARY" ) then
 22      l_action := l_action || " - " ||
 23                  "Salary for id " || :old.id ||
 24                  " changed from " || :old.salary ||
 25                  " to " || :new.salary;
 26    end if;
 27
 28    insert into employees_log(
 29      who, action, when )
 30      values(
 31        user, l_action, sysdate );
 32  end;
 33  /
SQL>
SQL> create trigger aiud_employees_copy
  2    after 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 := state_package.rows_changed || " were " || "inserted";
  9    elsif UPDATING then
 10      l_action := state_package.rows_changed || " were " || "updated";
 11    elsif DELETING then
 12      l_action := state_package.rows_changed || " were " || "deleted";
 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> update employees_copy set salary = salary * 0.95;
SQL>
SQL>
SQL> select * from employees_log;
WHO                            ACTION                                                                                       WHEN
------------------------------ ---------------------------------------------------------------------------------------------------- ---------
sqle                         Update - Salary for id 01 changed from 1234.56 to 1172.83                                    09-SEP-06
sqle                         Update - Salary for id 02 changed from 6661.78 to 6328.69                                    09-SEP-06
sqle                         Update - Salary for id 03 changed from 6544.78 to 6217.54                                    09-SEP-06
sqle                         Update - Salary for id 04 changed from 2344.78 to 2227.54                                    09-SEP-06
sqle                         Update - Salary for id 05 changed from 2334.78 to 2218.04                                    09-SEP-06
sqle                         Update - Salary for id 06 changed from 4322.78 to 4106.64                                    09-SEP-06
sqle                         Update - Salary for id 07 changed from 7897.78 to 7502.89                                    09-SEP-06
sqle                         Update - Salary for id 08 changed from 1232.78 to 1171.14                                    09-SEP-06
sqle                         8 were updated                                                                               09-SEP-06
SQL>
SQL>
SQL> drop table employees_copy;
SQL>
SQL> drop table employees_log;
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
SQL>
SQL>
SQL>
SQL>