PostgreSQL Triggers

A PostgreSQL trigger is a database object that automatically executes a function in response to an event such as insert, update, delete, or truncate. In this section, you will learn about triggers and how to use them effectively.

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Section 1. Basic PostgreSQL Triggers

Introduction to PostgreSQL trigger – Give you a brief overview of PostgreSQL triggers, why you should use triggers, and when to use them.
Create trigger – Show you how to create your first trigger in PostgreSQL.
Drop trigger– Describe steps for using the DROP TRIGGER statement to delete a trigger from a table.
Alter trigger – Guide you on how to use the ALTER TRIGGER statement to rename a trigger.

Section 2. INSERT triggers

BEFORE INSERT triggers – Show you how to create a trigger that is activated automatically before an INSERT event occurs on the associated table.
AFTER INSERT triggers – Guide you on defining a trigger activated automatically after an INSERT event occurs on the associated table.

Section 3. UPDATE triggers

BEFORE UPDATE triggers – Define a BEFORE UPDATE trigger that is activated before an update event occurs.
AFTER UPDATE triggers – Create an AFTER UPDATE trigger fired after an update event occurs.

Section 4. DELETE triggers

BEFORE DELETE triggers – Define a BEFORE DELETE trigger that fires before a delete event occurs.
AFTER DELETE triggers – Create an AFTER DELETE trigger fired after a delete event occurs.

Section 5. INSTEAD OF triggers

INSTEAD OF triggers – Show you how to use the INSTEAD OF trigger to customize the behavior of the INSERT, UPDATE, and DELETE operations on a view.

Section 6. TRUNCATE triggers

BEFORE TRUNDCATE Trigger – Create a trigger to response before a TRUNCATE event occurs.

Section 7. Enabling & Disabling triggers

Disable trigger – Show how to disable a trigger or all triggers that belong to a table.
Enable triggers – Learn how to enable a trigger or all triggers associated with a table.

Section 8. Listing triggers

Listing triggers – List all triggers associated with a table or all triggers in the current database.

Section 9. Advanced triggers

Event trigger – Introduce the event trigger that fires when an event related to a DDL statement occurs.
Conditional trigger – Define a conditional trigger that fires only when a condition is satisfied.