Transfer leaves account negative

Code reviewDatabases & SQLReliability & on-callMid–Senior~25 min

Review this Python funds-transfer.

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.

0:00 of about 25 min

Mark a line and say what kind of problem it is.0 findings

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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