Code reviewMediumcr-g092

Subject Missing rollbackLevel Mid–Senior~25 minCommon in Databases & SQL · Reliability & on-call interviewsIndustries Software development

Question

Review this Python funds-transfer.

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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 transfer(conn, src, dst, amount):2    cur = conn.cursor()3    cur.execute("UPDATE accounts SET bal = bal - %s WHERE id = %s", (amount, src))4    if cur.rowcount != 1:5        raise ValueError("source not found")6    cur.execute("UPDATE accounts SET bal = bal + %s WHERE id = %s", (amount, dst))7    if cur.rowcount != 1:8        raise ValueError("dest not found")9    conn.commit()

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