SQL · interview question
A bug appears around joins. What is the strongest first debugging move?
Multiple choiceMediumchapter-11-curatedpremiumsqljoins
SELECT o.id, c.email
FROM orders o
JOIN customers c ON c.id = o.customer_id;Answer and explanation
Correct answer
C. Trace one concrete example, inspect the state transitions, and compare them to the intended rule before rewriting anything.
Why
That approach is reliable because it creates evidence. Fear of joins often leads to duplicated data or multiple fragile follow-up queries.
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