Views and triggers
Views and Triggers: The Bridge between the Relational Model and the Outside World Views are virtual tables that provide a filtered and summarized view...
Views and Triggers: The Bridge between the Relational Model and the Outside World Views are virtual tables that provide a filtered and summarized view...
Views are virtual tables that provide a filtered and summarized view of the underlying relational data. They offer a specific perspective on the data, often focused on specific aspects or users.
Triggers are mechanisms that automatically execute when a specific event occurs on the underlying table. They act as triggers triggering an action or event based on the changed data.
Key differences:
Views:
Reflect data from one or more tables.
Allow selective access to specific data.
Can be used directly by applications or other users.
Triggers:
Act on the underlying table directly.
Trigger automatic actions when specific changes occur.
Often used to enforce data integrity rules or maintain data consistency.
Benefits of Views:
Data isolation: Views can be used to present a simplified view of the data to users without exposing the underlying complexity.
Security and performance: Views can be granted specific permissions, minimizing data exposure.
Flexibility: Views can be easily updated or modified to reflect changes in the underlying data.
Benefits of Triggers:
Data integrity: Triggers ensure data consistency and prevent invalid or inconsistent data entries.
Event-driven automation: Triggers allow for automatic responses to specific data changes, enabling real-time data processing.
Data security: Triggers can be used to restrict access to sensitive data or trigger alerts based on specific changes.
Examples:
View: A SalesView might display key customer data and their recent purchases.
Trigger: When a new customer is added to the Customers table, a trigger would automatically update the Orders table with the customer's ID and contact information.
Conclusion:
Views and triggers are powerful tools that bridge the gap between the relational model and the outside world. They offer flexibility, security, and data management capabilities that enhance the efficiency and reliability of data systems