[Solved] You wrote this AFTER INSERT trigger:CREATE TRIGGER trg_after_insert AFTER INSERT ON sales EXECUTE FUNCTION log_sale();But it gives an error. What is the likely cause? | PostgreSQL

PostgreSQL - Triggers in PostgreSQL

You wrote this AFTER INSERT trigger:

CREATE TRIGGER trg_after_insert AFTER INSERT ON sales EXECUTE FUNCTION log_sale();

But it gives an error. What is the likely cause?

ATable name 'sales' is reserved.

BMissing FOR EACH ROW or FOR EACH STATEMENT clause.

CAFTER triggers cannot be created on INSERT.

DTrigger function name is invalid.

Step-by-Step Solution

Solution:

Step 1: Check trigger syntax requirements
PostgreSQL requires specifying FOR EACH ROW or FOR EACH STATEMENT in CREATE TRIGGER.
Step 2: Identify missing clause
The given statement lacks this clause, causing syntax error.
Final Answer:
Missing FOR EACH ROW or FOR EACH STATEMENT clause. -> Option B
Quick Check:
Trigger syntax requires FOR EACH ROW/STATEMENT [OK]

Quick Trick: Always specify FOR EACH ROW or FOR EACH STATEMENT in triggers [OK]

Common Mistakes:

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You wrote this AFTER INSERT trigger: