Importance of Statement-Level Triggers

*NOTE: Assume that you have created a database for some customers with constraints like, orders, sales etc.

• Enforcement of Complex Data Rules: They can enforce complex data rules beyond what constraints can handle like deleting a customer’s entry in database and automatically removing their related orders.
• Automation of Tasks: They tend to automate tasks based on database events (Insert, Update, Delete). Perhaps it can update a “total sales” table whenever a new order is placed, saving oneself, the time and effort to write a separate code to maintain accurate sales figures.
• Centralization of Actions: They can centralize actions into reusable code blocks, making your code neat, easy to read & understand, and manage. One has to create multiple procedures that need to perform common actions like logging changes after inserting data into different tables. Instead of duplicating that code, one create a trigger that fires after any insert operation and performs the centralized logging action.
• Enhanced Security: They can perform extra security checks and/or validate data to prevent unauthorized access or vulnerabilities. If a trigger could be set to fire before deleting a user account, then it could check if the user, attempting the deletion, has the necessary privileges to perform such an action.

Statement-level triggers in Oracle databases execute actions for each transaction, responding to various database events like DML and DDL statements, system events, and user interactions. They act as programmed responses to specific table events, enhancing database management and automation.

Stored as named PL/SQL blocks, triggers execute automatically upon occurrence of a predefined event, crucial for efficient database operation.

In this article, we will cover PL/SQL Statement level Triggers syntax, their importance, characteristics, common use cases, and examples, illustrating their role in Oracle database management.