Code reviewMediumcr-g287

Subject N plus one queriesLevel Mid–Senior~18 minCommon in Code quality & review interviewsIndustries Software development, Technology

Question

Review this Python data-access function that returns recent active orders for one customer. The orders table has tens of millions of rows.

What a strong answer looks like

Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.

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Code to reviewpython

1def recent_active_orders(db, customer_id, since):2    rows = db.execute("SELECT * FROM orders").fetchall()3    result = []4    for r in rows:5        if r["customer_id"] == customer_id and r["status"] == "active" and r["created_at"] >= since:6            result.append(r)7    return result

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