1. PL/SQL Programing : Triggers

2. Agenda What is a Trigger? Why use them? How do they work?
Purposes of Triggers

3. What is a Trigger?
Code which is executed or fired automatically when a particular type of SQL statement is executed.
Triggers consist of timing conditions and actions
When this happens
Do this
Guide to Oracle 10g

4. What can you do with Them?
Clean up data as its entered
Add data to one table based on changes in another.
Guide to Oracle 10g

5. Trigger Syntax
CREATE OR REPLACE TRIGGER trigger_name {BEFORE|AFTER} {INSERT|UPDATE|DELETE} [OF columns] ON table_name [FOR EACH ROW [WHEN (condition)]] BEGIN Trigger PL/SQL Code goes here; END;

6. Correlation Identifiers
DML Event
:OLD
:NEW
INSERT
n/a
Contains insert values (new only)
UPDATE
Values of the original row
Values of the updated row
DELETE

7. Example Trigger
Guide to Oracle 10g

8. Add Credit card Support to FUDGEMART
Demo
Add Credit card Support to FUDGEMART

9. Questions