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Code RoomSELECT * fetches unused columns
MediumPrep Room Coding #2266

SELECT * fetches unused columns

Code reviewDatabases & SQLMid–Senior~20 min

Review this Java DAO method that checks whether a user can log in.

The `users` table has a 4KB `bio` TEXT column, a `profile_json` JSONB column, and an avatar BYTEA.

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 20 min
Mark a line and say what kind of problem it is.0 findings
1public boolean isActive(long userId) {
2 String sql = "SELECT * FROM users WHERE id = ?";
3 try (PreparedStatement ps = conn.prepareStatement(sql)) {
4 ps.setLong(1, userId);
5 try (ResultSet rs = ps.executeQuery()) {
6 if (rs.next()) {
7 return "active".equals(rs.getString("status"));
8 }
9 return false;
10 }
11 }
12}
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.