Creating a Trigger: AFTER INSERT OR DELETE OR UPDATE ON employee : After Event Trigger « Trigger « Oracle PL/SQL Tutorial






SQL>
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>
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

3 rows selected.

SQL>
SQL>
SQL>
SQL> CREATE OR REPLACE TRIGGER UpdateMajorStats
  2    AFTER INSERT OR DELETE OR UPDATE ON employee
  3  DECLARE
  4    total_employee NUMBER;
  5
  6    CURSOR c_Statistics IS
  7      SELECT city, COUNT(*) total_employee,
  8             SUM(salary) total_salary
  9        FROM employee
 10        GROUP BY city;
 11  BEGIN
 12    FOR v_StatsRecord in c_Statistics LOOP
 13      DBMS_OUTPUT.put_line(v_StatsRecord.total_salary);
 14      DBMS_OUTPUT.put_line(v_StatsRecord.total_employee);
 15      DBMS_OUTPUT.put_line(v_StatsRecord.city);
 16
 17      IF SQL%NOTFOUND THEN
 18        DBMS_OUTPUT.put_line(v_StatsRecord.city);
 19        DBMS_OUTPUT.put_line(v_StatsRecord.total_salary);
 20        DBMS_OUTPUT.put_line(v_StatsRecord.total_employee);
 21      END IF;
 22    END LOOP;
 23  END UpdateMajorStats;
 24  /

Trigger created.

SQL>
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  /
1234.56
1
Toronto
15551.34
3
Vancouver

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  /
1234.56
1
Toronto
17886.12
4
Vancouver

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  /
4322.78
1
New York
1234.56
1
Toronto
17886.12
4
Vancouver

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  /
12220.56
2
New York
1234.56
1
Toronto
17886.12
4
Vancouver

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  /
12220.56
2
New York
1234.56
1
Toronto
19118.9
5
Vancouver

1 row created.

SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /

Table dropped.

SQL>








28.7.After Event Trigger
28.7.1.After delete trigger
28.7.2.After update trigger
28.7.3.Using an AFTER EVENT Trigger
28.7.4.Creating a Trigger: AFTER INSERT OR DELETE OR UPDATE ON employee
28.7.5.Trigger for certain columns
28.7.6.AFTER INSERT OR UPDATE ON tableName
28.7.7.after insert trigger