Database objects like Views, Procedures, and Triggers allow you to store logic directly within the database engine. This can improve security, simplify application code, and ensure business rules are always followed.
The Power of Encapsulation
- Views: Create virtual tables to simplify complex queries for end-users or applications.
- Stored Procedures: Group multiple SQL statements into a single, callable unit for complex business flows.
- Triggers: Automatically react to data changes (like logging deletes or updating a modified_at timestamp).
When to Use Database Logic
| Pros | Cons |
|---|---|
| Reduced network traffic (logic runs in DB) | Harder to version control |
| Centralised business rules | Logic hidden from application developers |
| Security (grant view access, not table access) | Can become a performance bottleneck |
| Prevent SQL injection via parameterised procedures | Debugging is more difficult |
Module Roadmap
| Topic | Description | Interview Weight |
|---|---|---|
| Views & Materialized Views | Virtual tables, security, performance | High |
| Stored Procedures & Functions | Server-side logic, dynamic SQL | High |
| Triggers & Cursors | Automation, row-level processing | Medium |
Q: Why use a Stored Procedure instead of writing the logic in your app (Node.js/Python)?
A: * Performance: Reduces network round-trips for multi-step tasks. * Security: prevents SQL injection and allows restricting users to only execute specific procedures without knowing the table structure.
Q: Does a View store data? A: No. A standard VIEW is just a saved query. Every time
you query the view, the database runs the underlying query. Only Materialized Views store
actual data on disk.
Q: When should you NOT use a trigger? A: Avoid triggers for complex business logic that
should be in the application layer. Triggers are hard to debug, hard to test, and can cause unexpected side effects (e.g., cascading triggers slowing down inserts).
Premium Content
Unlock Views, Procedures & Triggers Overview and all premium lessons with a subscription.
From ₹199.99/year — See plans