mysql subquery

bagaimana mengatasi error Subquery returns more than 1 row di mysql ? berikut lampiran query nya :

 $query = $this->db->query('SELECT tanggal,
                ( SELECT COUNT(*) from absensi_siswa where kehadiran="alfa" GROUP BY tanggal ) AS alfa,
                ( SELECT COUNT(*) from absensi_siswa where kehadiran="izin" GROUP BY tanggal ) AS izin,
                ( SELECT COUNT(*) from absensi_siswa where kehadiran="hadir" GROUP BY tanggal ) AS hadir,
                ( SELECT COUNT(*) from absensi_siswa where kehadiran="sakit" GROUP BY tanggal ) AS sakit
                FROM absensi_siswa GROUP BY tanggal');
        return $query->result();