How to create an Oracle audit trigger? - sql

Question

CREATE OR REPLACE TRIGGER EVALUATION
BEFORE INSERT OR UPDATE OR DELETE ON BOOKING
FOR EACH ROW
DECLARE
BEGIN
SELECT BOOKING_EVALUATION FROM BOOKING WHERE BOOKING_EVALUATION > 2;
SELECT BOOKING_EVALUATION INTO EVALUATIONAUDIT FROM BOOKING;
IF INSERTING THEN
INSERT INTO EVALUATIONAUDIT (VOYAGES_ID,CUSTOMER_NAME,START_DATE,SHIP_NAME,BOOKING_EVALUATION)
VALUES(:NEW.VOYAGES_ID,:NEW.CUSTOMER_NAME,:NEW.START_DATE,:NEW.SHIP_NAME,:NEW.BOOKING_EVALUATION);
END IF;
IF UPDATING THEN
INSERT INTO EVALUATIONAUDIT (VOYAGES_ID,CUSTOMER_NAME,START_DATE,SHIP_NAME,BOOKING_EVALUATION)
VALUES(:OLD.VOYAGES_ID,:OLD.CUSTOMER_NAME,:OLD.START_DATE,:OLD.SHIP_NAME,:OLD.BOOKING_EVALUATION);
END IF;
IF DELETING THEN
INSERT INTO EVALUATIONAUDIT (VOYAGES_ID,CUSTOMER_NAME,START_DATE,SHIP_NAME,BOOKING_EVALUATION)
VALUES(:OLD.VOYAGES_ID,:OLD.CUSTOMER_NAME,:OLD.START_DATE,:OLD.SHIP_NAME,:OLD.BOOKING_EVALUATION);
END IF;
END;
This is my audit table:
desc evaluationaudit;
Name Null? Type
----------------------------------------- -------- -----------------------
AUDITT_ID NOT NULL NUMBER(10)
VOYAGES_ID NOT NULL NUMBER(10)
CUSTOMER_NAME NOT NULL VARCHAR2(20)
START_DATE NOT NULL DATE
SHIP_NAME NOT NULL VARCHAR2(20)
BOOKING_EVALUATION NOT NULL NUMBER(20)
and this is my show error output:
SQL> SHOW ERRORS;
Errors for TRIGGER EVALUATION:
LINE/COL ERROR
-------- -------------------------------------------------------------
12/24 PLS-00049: bad bind variable 'NEW.CUSTOMER_NAME'
12/43 PLS-00049: bad bind variable 'NEW.START_DATE'
12/59 PLS-00049: bad bind variable 'NEW.SHIP_NAME'
18/24 PLS-00049: bad bind variable 'OLD.CUSTOMER_NAME'
18/43 PLS-00049: bad bind variable 'OLD.START_DATE'
18/59 PLS-00049: bad bind variable 'OLD.SHIP_NAME'
24/24 PLS-00049: bad bind variable 'OLD.CUSTOMER_NAME'
24/43 PLS-00049: bad bind variable 'OLD.START_DATE'
24/59 PLS-00049: bad bind variable 'OLD.SHIP_NAME'
I wanted to add to the audit table. If a customer gives a poor evaluation of 2 or less, the details of their voyage (customer_name, name and date of the cruise, ship name and evaluation) but I'm getting error
Warning: Trigger created with compilation errors.
And the audit table is empty, showing no rows selected. I can't seem to find the problem where I am going wrong.

Answer 1

Maybe the following code snippets will help you. Suppose we have 2 tables: BOOKING, and EVALUATION_AUDIT (everything written in uppercase letters is taken from the code in your question).
Tables
create table booking (
VOYAGES_ID number primary key
, CUSTOMER_NAME VARCHAR2(20) NOT NULL
, START_DATE DATE NOT NULL
, SHIP_NAME VARCHAR2(20) NOT NULL
, BOOKING_EVALUATION NUMBER(20) NOT NULL
) ;
create table evaluationaudit (
AUDITT_ID number generated always as identity start with 5000 primary key
, trg_cond_pred varchar2( 64 ) default 'Row not added by evaluation trigger!'
, VOYAGES_ID NUMBER(10) NOT NULL
, CUSTOMER_NAME VARCHAR2(20) NOT NULL
, START_DATE DATE NOT NULL
, SHIP_NAME VARCHAR2(20) NOT NULL
, BOOKING_EVALUATION NUMBER(20) NOT NULL
) ;
Trigger
-- "updating" and "deleting" code omitted for clarity
CREATE OR REPLACE TRIGGER EVALUATION_trigger
BEFORE INSERT OR UPDATE OR DELETE ON BOOKING
FOR EACH ROW
BEGIN
case
when INSERTING then
if :new.booking_evaluation <= 2 then
INSERT INTO EVALUATIONAUDIT
( trg_cond_pred,
VOYAGES_ID, CUSTOMER_NAME, START_DATE, SHIP_NAME, BOOKING_EVALUATION )
VALUES (
'INSERTING'
, :NEW.VOYAGES_ID
, :NEW.CUSTOMER_NAME
, :NEW.START_DATE
, :NEW.SHIP_NAME
, :NEW.BOOKING_EVALUATION
);
end if ;
end case ;
END ;
/
Testing
One of your requirements (in your question) is:
I wanted to add to the audit table. If a customer gives a poor
evaluation of 2 or less, the details of their voyage (customer_name,
name and date of the cruise, ship name and evaluation)
delete from evaluationaudit ;
delete from booking ;
-- booking_evaluation greater than 2 -> no entry in audit table
insert into booking
( VOYAGES_ID, CUSTOMER_NAME, START_DATE, SHIP_NAME, BOOKING_EVALUATION )
values ( 1111, 'customer1', date '2018-05-24', 'ship1', 9999 ) ;
select * from evaluationaudit ;
-- no rows selected
-- booking_evalution = 2 -> insert a row into the audit table
insert into booking
( VOYAGES_ID, CUSTOMER_NAME, START_DATE, SHIP_NAME, BOOKING_EVALUATION )
values ( 1112, 'customer1', date '2018-05-24', 'ship1', 2 ) ;
select * from evaluationaudit ;
AUDITT_ID TRG_COND_PRED VOYAGES_ID CUSTOMER_NAME START_DATE SHIP_NAME BOOKING_EVALUATION
5000 INSERTING 1112 customer1 24-MAY-18 ship1 2
__Update__
If - as you wrote in your comment - you need to pull in some more data from other tables, maybe you want to try the following approach: keep the trigger code rather brief, and use it to call a procedure for the more complicated stuff eg
Tables
create table evaluationaudit (
AUDITT_ID number generated always as identity start with 7000 primary key
, trg_cond_pred varchar2( 64 ) default 'Row not added by evaluation trigger!'
, VOYAGES_ID NUMBER NOT NULL
, CUSTOMER_NAME VARCHAR2(20) NOT NULL
, SHIP_NAME VARCHAR2(20) NOT NULL
, BOOKING_EVALUATION NUMBER(20) NOT NULL
) ;
create table ships ( name varchar2( 64 ), id number unique ) ;
create table customers ( name varchar2( 64 ), id number unique ) ;
insert into ships ( name, id ) values ( 'ship1', 501 );
insert into ships ( name, id ) values ( 'ship2', 502 );
insert into ships ( name, id ) values ( 'ship3', 503 );
insert into customers ( name, id ) values ( 'customer1', 771 ) ;
insert into customers ( name, id ) values ( 'customer2', 772 ) ;
insert into customers ( name, id ) values ( 'customer3', 773 ) ;
create table bookings (
id number generated always as identity start with 5000 primary key
, voyagesid number
, shipid number
, customerid number
, evaluation number
, bookingdate date
);
Trigger
create or replace trigger bookingeval
before insert on bookings
for each row
when ( new.evaluation <= 2 ) -- Use NEW without colon here! ( see documentation )
begin
auditproc( :new.voyagesid, :new.customerid, :new.shipid, :new.evaluation ) ;
end ;
/
Procedure
create or replace procedure auditproc (
voyagesid_ number
, customerid_ number
, shipid_ number
, evaluation_ number
)
as
customername varchar2( 64 ) := '' ;
shipname varchar2( 64 ) := '' ;
begin
-- need to find the customername and shipname before INSERT
select name into customername from customers where id = customerid_ ;
select name into shipname from ships where id = shipid_ ;
insert into evaluationaudit
( trg_cond_pred,
voyages_id, customer_name, ship_name, booking_evaluation )
values (
'INSERTING'
, voyagesid_
, customername
, shipname
, evaluation_
);
end ;
/
Testing
-- evaluation > 2 -> no INSERT into evaluationaudit
insert into bookings
( voyagesid, customerid, shipid, evaluation, bookingdate )
values ( 1111, 771, 501, 9999, sysdate ) ;
select * from evaluationaudit ;
-- no rows selected
-- evaluation = 2
-- -> trigger calling audit procedure -> inserts into evaluationaudit
insert into bookings
( voyagesid, customerid, shipid, evaluation, bookingdate )
values ( 1112, 772, 502, 2, sysdate ) ;
select * from evaluationaudit ;
AUDITT_ID TRG_COND_PRED VOYAGES_ID CUSTOMER_NAME SHIP_NAME BOOKING_EVALUATION
7000 INSERTING 1112 customer2 ship2 2