[Solved] You wrote this trigger but it causes a runtime error:CREATE TRIGGER trg_log AFTER INSERT ON sales FOR EACH ROW BEGIN INSERT INTO sales_log VALUES (NEW.... END;What is the likely cause of the error? | SQL

SQL - Triggers

You wrote this trigger but it causes a runtime error:

CREATE TRIGGER trg_log AFTER INSERT ON sales FOR EACH ROW BEGIN INSERT INTO sales_log VALUES (NEW.id, NEW.amount); UPDATE sales SET amount = amount * 1.1 WHERE id = NEW.id; END;

What is the likely cause of the error?

ATrigger tries to update the same table it is triggered on, causing recursion

BMissing semicolon after INSERT statement

CNEW keyword cannot be used in AFTER INSERT triggers

Dsales_log table does not exist

Step-by-Step Solution

Solution:

Step 1: Identify trigger actions
The trigger inserts into sales_log and then updates sales table, which is the same table that fired the trigger.
Step 2: Understand recursion risk
Updating sales inside an AFTER INSERT trigger on sales causes the trigger to fire again, leading to infinite recursion and runtime error.
Final Answer:
Trigger tries to update the same table it is triggered on, causing recursion -> Option A
Quick Check:
Updating trigger table inside trigger causes recursion error [OK]

Quick Trick: Avoid updating trigger table inside its own trigger [OK]

Common Mistakes:

Ignoring recursion from updating same table
Assuming missing semicolon causes runtime error
Believing NEW is invalid in AFTER INSERT triggers

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You wrote this trigger but it causes a runtime error:

Step 1: Identify trigger actions

Step 2: Understand recursion risk

Final Answer:

Quick Check:

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