MySQL:Menemukan nama berulang di tabel Pengguna saya

SELECT u.*
FROM cpnc_User u JOIN
(
    SELECT firstName, lastName
    FROM cpnc_User
    GROUP BY firstName, lastName
    HAVING COUNT(*) > 1
) X on X.firstName = u.firstName AND x.lastName = u.lastName
ORDER BY u.firstName, u.lastName

Tidak perlu membuat bidang gabungan, cukup gunakan 2 bidang secara terpisah