Differentiate between database triggers and application triggers in PL/SQL.

In PL/SQL (Procedural Language/Structured Query Language), triggers are used to automate actions or tasks based on specific events occurring in the database. Triggers can be classified into two main types: database triggers and application triggers. Here's an in-depth explanation of the differences between these two types of triggers:

1. Database Triggers:

* Database triggers are defined and managed within the database itself.
* They are associated with a specific table, view, or database event and are triggered automatically when the defined event occurs.
* Database triggers are stored in the database and executed by the database engine.
* They are typically used to enforce data integrity rules, perform data validation, or capture and log changes in the database.
* Database triggers are created and managed using SQL statements within the database, such as CREATE TRIGGER and ALTER TRIGGER.
* Database triggers can be defined for events such as INSERT, UPDATE, DELETE, or DDL (Data Definition Language) statements like CREATE, ALTER, or DROP.
2. Application Triggers:

* Application triggers, also known as client-side triggers or form triggers, are associated with specific actions or events within an application.
* They are defined and managed within the application code and executed by the application itself.
* Application triggers are typically used to control user interface behavior, validate user input, perform application-specific actions, or implement custom business rules.
* They are commonly used in applications developed using tools like Oracle Forms, Oracle Application Express (APEX), or other client-side frameworks.
* Application triggers are created and managed within the application development environment, using tools or languages specific to that environment.
* They are not stored in the database but are part of the application codebase.

Key Differences:

1. Location and Execution: Database triggers reside and execute within the database engine, whereas application triggers are part of the application code and executed within the application environment.
2. Event Association: Database triggers are associated with database events or actions (e.g., data manipulation or data definition), while application triggers are associated with application-specific events (e.g., button clicks, form submission, or user interactions).
3. Scope and Portability: Database triggers are applicable to all applications accessing the database, making them more portable and independent of specific application implementations. On the other hand, application triggers are specific to the application they are implemented in and not accessible outside of it.
4. Control and Flexibility: Database triggers are powerful for enforcing database-level constraints and maintaining data integrity. They have access to a wide range of database objects and functionality. Application triggers, on the other hand, provide control over the application behavior and are typically focused on user interactions and application-specific business rules.

In summary, database triggers are managed and executed within the database, associated with database events, and used for enforcing data integrity and capturing changes. Application triggers, on the other hand, are part of the application code, associated with application events, and used for controlling user interface behavior and implementing application-specific logic. Understanding the differences between these two types of triggers is crucial when designing and implementing automation and business logic within PL/SQL applications.