🎁 New User? Get 20% off your first purchase with code NEWUSER20 · ⚡ Instant download · 🔒 Secure checkout Register Now →
Menu

Categories

Databases Intermediate

What is Trigger?

A database object that automatically executes a specified function when certain events (INSERT, UPDATE, DELETE) occur on a table.

Triggers run automatically in response to data changes. They can execute BEFORE or AFTER the triggering event, and operate on each row or once per statement. Common uses include audit logging, data validation, maintaining derived data, and enforcing complex business rules.

In PostgreSQL, triggers call trigger functions written in PL/pgSQL. While powerful, overuse of triggers can make database behavior hard to debug and predict. Consider application-level logic for complex business rules.

Related Terms

Connection Pool
A cache of database connections that can be reused, avoiding the overhead of creating new connections for each request.
JOIN
An SQL operation that combines rows from two or more tables based on a related column between them.
Cursor
A database object that enables row-by-row processing of query results, useful for operations that cannot be done in bulk.
Window Function
An SQL function that performs calculations across a set of rows related to the current row without collapsing the result set.
Prepared Statement
A pre-compiled SQL template that uses parameters instead of literal values, preventing SQL injection and improving performance.
Row-Level Security (RLS)
A database feature that restricts which rows a user can access in a table based on security policies.
 View All Databases Terms →