mysql join case count with single query - mysql

Question

i am very new to programming and now i have problem to solve it quickly. Trying for 1weeks only and give some result that can satisfy me. Any one can help me with this, heres my table and result that i wanted to show:
enter image description here
this the result
the problem ss
i am trying and trying this code for more than a weeks and its still nothing:
enter code here SELECT idkt.id,
idkt.nama,
idkt.satuan,
trgt.nilai ,
tbl.*,
ROUND((tbl.Triwulan_1 / trgt.nilai * 100), 2) Persen_1,
ROUND((tbl.Triwulan_2 / trgt.nilai * 100), 2) Persen_2,
ROUND((tbl.Triwulan_3 / trgt.nilai * 100), 2) Persen_3,
ROUND((tbl.Triwulan_4 / trgt.nilai * 100), 2) Persen_4
FROM indikator idkt
left JOIN (
SELECT id_indikator,
YEAR(tgl) tahun,
SUM(CASE
WHEN MONTH(tgl) BETWEEN 1 AND 3 THEN
1
END) AS Triwulan_1,
SUM(CASE
WHEN MONTH(tgl) BETWEEN 4 AND 6 THEN
1
END) AS Triwulan_2,
SUM(CASE
WHEN MONTH(tgl) BETWEEN 7 AND 9 THEN
1
END) AS Triwulan_3,
SUM(CASE
WHEN MONTH(tgl) BETWEEN 10 AND 12 THEN
1
END) AS Triwulan_4
FROM msttrans
WHERE YEAR(tgl) = ".$tahun."
GROUP BY id_indikator, YEAR(tgl)) tbl
ON (idkt.id = tbl.id_indikator)
left JOIN target trgt
ON (trgt.id_indikator = idkt.id
AND YEAR(trgt.tahun) = tbl.tahun)
left JOIN (select target.nilai as fnilai from target where id_indikator is not NULL) trgt on trgt.id_indikator = idkt.id
ORDER BY idkt.id ASC

Answer 1

If any inputs to arithmetic expressions like
ROUND((tbl.Triwulan_1 / trgt.nilai * 100), 2)
are null, the resulting expression will also be null. You probably should try changing these sorts of expressions from
SUM(CASE WHEN MONTH(tgl) BETWEEN 1 AND 3 THEN 1 END) AS Triwulan_1
to
SUM(CASE WHEN MONTH(tgl) BETWEEN 1 AND 3 THEN 1 ELSE 0 END) AS Triwulan_1
to avoid too many attempts to work with null values.
Also, you should troubleshoot by testing your inner queries one-by-one. Make sure they work (especially the one containing GROUP BY) before you use it in a join.
Edit LEFT JOIN operations with ON conditions that don't match any rows return null values for the columns in the left table. This is a common source of unexpected null values. (If you use JOIN in place of LEFT JOIN the query suppresses rows from the right table if they don't match the left table.)
You could troubleshoot these nulls with expressions like this.
SELECT ... tbl.Triwulan_1, trgt.nilai, ROUND((tbl.Triwulan_1 / trgt.nilai * 100), 2), ...