Menampilkan data yang digabung dengan menggunakan query union pada report laporan

Assalamu'alaikum... Selamat Siang...

Saya menggunakan query union untuk menggabungkan data dari 3 tabel yang berbeda. Namun ketika saya gunakan query tersebut pada report cetak laporan, data yang muncul hanya data dari 1 tabel laporan. adapun script gabungan tersebut adalah sebagai berikut :

$query = $this->db->query("SELECT * FROM tb_laporan3 AS tb3
JOIN tb_indikator  AS a ON tb3.id_indikator=a.id_indikator
JOIN tb_subprogram AS b ON tb3.id_subprogram=b.id_subprogram
JOIN tb_program    AS c ON tb3.id_program   =c.id_program
JOIN tb_organisasi AS d ON tb3.id_organisasi=d.id_organisasi
JOIN tb_suburusan  AS e ON tb3.id_suburusan =e.id_suburusan
JOIN tb_suburusan2 AS f ON tb3.id_suburusan2=f.id_suburusan2
JOIN tb_suburusan3 AS g ON tb3.id_suburusan3=g.id_suburusan3
JOIN tb_urusan     AS h ON tb3.id=h.id
UNION
SELECT * FROM tb_laporan2 AS tb2
JOIN tb_indikator  AS a ON tb2.id_indikator=a.id_indikator
JOIN tb_subprogram AS b ON tb2.id_subprogram=b.id_subprogram
JOIN tb_program    AS c ON tb2.id_program =c.id_program
JOIN tb_organisasi AS d ON tb2.id_organisasi=d.id_organisasi
JOIN tb_suburusan  AS e ON tb2.id_suburusan =e.id_suburusan
JOIN tb_suburusan2 AS f ON tb2.id_suburusan2=f.id_suburusan2
JOIN tb_suburusan3 AS g ON tb2.id_suburusan3=g.id_suburusan3
JOIN tb_urusan     AS h ON tb2.id=h.id
UNION
SELECT * FROM tb_laporan AS tb
JOIN tb_indikator  AS a ON tb.id_indikator=a.id_indikator
JOIN tb_subprogram AS b ON tb.id_subprogram=b.id_subprogram
JOIN tb_program    AS c ON tb.id_program =c.id_program
JOIN tb_organisasi AS d ON tb.id_organisasi=d.id_organisasi
JOIN tb_suburusan  AS e ON tb.id_suburusan =e.id_suburusan
JOIN tb_suburusan2 AS f ON tb.id_suburusan2=f.id_suburusan2
JOIN tb_suburusan3 AS g ON tb.id_suburusan3=g.id_suburusan3
JOIN tb_urusan     AS h ON tb.id=h.id");

Adapun script pada cetak laporan untuk memanggil data dari 3 tbl laporan adalah sebagai berikut:

<?php
$tb_laporan = $this->db->query("SELECT sum(t_rpjmdrp) as t_rpjmdrp FROM tb_laporan a
              JOIN tb_indikator b  ON b.id_indikator =a.id_indikator
              JOIN tb_subprogram c ON c.id_subprogram=a.id_subprogram
              JOIN tb_program d    ON d.id_program   =a.id_program
              JOIN tb_organisasi e ON e.id_organisasi=a.id_organisasi
              JOIN tb_suburusan f  ON f.id_suburusan =a.id_suburusan
              JOIN tb_suburusan2 g ON g.id_suburusan2=a.id_suburusan2
              JOIN tb_suburusan3 h ON h.id_suburusan3=a.id_suburusan3
              JOIN tb_urusan i     ON i.id=a.id
WHERE MONTH(a.tanggal)='".$this->input->post('bulan')."' AND YEAR(a.tanggal)='".$this->input->post('tahun')."' AND a.id_organisasi='".$rows1->id_organisasi."'")->row_array();

            echo number_format($tb_laporan['t_rpjmdrp']);
?>