Oracle PL/SQL - DELETEトリガーの後の例

CREATE TABLE medical_bills
(
    BILL_ID number(10) primary key,
    BILL_NUMBER varchar2(20),
    PARTY_NAME varchar2(50),
    BILL_DATE date,
    CREATED_BY varchar2(20),
    CREATED_DATE date
);

CREATE TABLE medical_bills_history
(
    BILL_ID number(10),
    BILL_NUMBER varchar2(20),
    PARTY_NAME varchar2(50),
    BILL_DATE date,
    DELETED_BY varchar2(20),
    DELETED_DATE date
);

CREATE OR REPLACE TRIGGER trg_after_delete_bill
AFTER DELETE
  ON medical_bills
  FOR EACH ROW
DECLARE
username varchar2(10);

BEGIN

  -- current login user, in this example, system
  SELECT user INTO username FROM dual;

  -- Insert OLD values in history table with username of user performing delete and sysdate as deleted_Date.
  INSERT INTO medical_bills_history VALUES(:OLD.BILL_ID,
           :OLD.BILL_NUMBER,:OLD.PARTY_NAME,:OLD.BILL_DATE,username,sysdate);

END;

INSERT INTO MEDICAL_BILLS values (1,'BILL101','Peter Thomas','12-MAY-2016','HR',sysdate);

INSERT INTO MEDICAL_BILLS values (2,'BILL102','Jemes Petil','10-JUN-2016','HR',sysdate);

INSERT INTO MEDICAL_BILLS values (3,'BILL103','Fujit su','10-JUL-2015','HR',sysdate);

select * from MEDICAL_BILLS;

select * from MEDICAL_BILLS_HISTORY;

-- no result

DELETE FROM MEDICAL_BILLS WHERE bill_id = 1;

DELETE FROM MEDICAL_BILLS WHERE bill_id = 3;

select * from MEDICAL_BILLS;

select * from MEDICAL_BILLS_HISTORY;