[Solved] You wrote this trigger function:CREATE FUNCTION validate_age() RETURNS trigger AS $ BEGIN IF NEW.age < 18 THEN RAISE EXCEPTION 'Age must be 18 or older'; END IF; RETURN NEW; END;... | PostgreSQL

PostgreSQL - Triggers in PostgreSQL

You wrote this trigger function:

CREATE FUNCTION validate_age() RETURNS trigger AS $$ BEGIN IF NEW.age < 18 THEN RAISE EXCEPTION 'Age must be 18 or older'; END IF; RETURN NEW; END; $$ LANGUAGE plpgsql;

But when inserting age = 15, no error occurs. What is the likely mistake?

ARAISE EXCEPTION syntax is incorrect

BThe trigger is not attached to the table

CThe function does not return NEW

DThe trigger function is missing LANGUAGE plpgsql

Step-by-Step Solution

Solution:

Step 1: Check function correctness
The function correctly raises exception and returns NEW, syntax is fine.
Step 2: Consider trigger attachment
If no error occurs, likely the trigger is not linked to the table to run the function.
Final Answer:
The trigger is not attached to the table -> Option B
Quick Check:
Trigger must be attached to run function [OK]

Quick Trick: Attach trigger to table to activate validation [OK]

Common Mistakes:

Forgetting to create the trigger after function
Assuming function runs without trigger
Misreading RAISE EXCEPTION syntax

Master "Triggers in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

You wrote this trigger function:

Step 1: Check function correctness

Step 2: Consider trigger attachment

Final Answer:

Quick Check:

Want More Practice?