Prep Room
Sign inCreate account
Code Room
Code reviewHardcr-g647
Subject Transaction phantom readLevel Senior–Staff~28 minCommon in Databases & SQL interviewsIndustries Software development

Question

Review this Go signup function that enforces one account per email.

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.

Learn the concepts
Talk through your review
Code to reviewgo
func CreateUser(ctx context.Context, db *sql.DB, email, name string) error {    tx, _ := db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadCommitted})    var n int    tx.QueryRowContext(ctx,        "SELECT COUNT(*) FROM users WHERE email = $1", email).Scan(&n)    if n > 0 {        tx.Rollback()        return ErrEmailTaken    }    _, err := tx.ExecContext(ctx,        "INSERT INTO users (email, name) VALUES ($1, $2)", email, name)    if err != nil {        tx.Rollback()        return err    }    return tx.Commit()}
Run or narrate your approach, then ask the coach.