Mega Code Archive

Reference old and new value by column in a before update Trigger

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 / Table created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 / 1 row created. 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 8 rows selected. SQL> SQL> -- BEFORE UPDATE Trigger SQL> CREATE OR REPLACE TRIGGER employee_before_update 2 BEFORE UPDATE 3 ON employee 4 FOR EACH ROW 5 6 DECLARE 7 v_username varchar2(10); 8 9 BEGIN 10 -- Find username of person performing UPDATE on the table 11 SELECT user INTO v_username 12 FROM dual; 13 14 dbms_output.put_line('By: '||v_username); 15 dbms_output.put_line('Date: '||sysdate); 16 dbms_output.put_line(':new.id: '||:new.id); 17 dbms_output.put_line(':new.first_name: '||:new.first_name); 18 dbms_output.put_line(':new.last_name: '||:new.last_name); 19 dbms_output.put_line(':old.id: '||:old.id); 20 dbms_output.put_line(':old.first_name: '||:old.first_name); 21 dbms_output.put_line(':old.last_name: '||:old.last_name); 22 23 END; 24 / Trigger created. SQL> SQL> update employee set first_name='newName'; By: RNTSOFT Date: 09-SEP-06 :new.id: 01 :new.first_name: newName :new.last_name: Martin :old.id: 01 :old.first_name: Jason :old.last_name: Martin By: RNTSOFT Date: 09-SEP-06 :new.id: 02 :new.first_name: newName :new.last_name: Mathews :old.id: 02 :old.first_name: Alison :old.last_name: Mathews By: RNTSOFT Date: 09-SEP-06 :new.id: 03 :new.first_name: newName :new.last_name: Smith :old.id: 03 :old.first_name: James :old.last_name: Smith By: RNTSOFT Date: 09-SEP-06 :new.id: 04 :new.first_name: newName :new.last_name: Rice :old.id: 04 :old.first_name: Celia :old.last_name: Rice By: RNTSOFT Date: 09-SEP-06 :new.id: 05 :new.first_name: newName :new.last_name: Black :old.id: 05 :old.first_name: Robert :old.last_name: Black By: RNTSOFT Date: 09-SEP-06 :new.id: 06 :new.first_name: newName :new.last_name: Green :old.id: 06 :old.first_name: Linda :old.last_name: Green By: RNTSOFT Date: 09-SEP-06 :new.id: 07 :new.first_name: newName :new.last_name: Larry :old.id: 07 :old.first_name: David :old.last_name: Larry By: RNTSOFT Date: 09-SEP-06 :new.id: 08 :new.first_name: newName :new.last_name: Cat :old.id: 08 :old.first_name: James :old.last_name: Cat 8 rows updated. SQL> SQL> SQL> -- clean the table SQL> drop table Employee 2 / Table dropped. SQL>