I've joined 2 tables (detail_pemesanan and pemesanan) and I want to do some operation with data from detail_pemesanan table, but it doesn't work
This is the join query
$data = DB::table('detail_pemesanan')
->join('pemesanan', 'detail_pemesanan.id_pemesanan', '=', 'pemesanan.id_pemesanan')
->select('pemesanan.tgl_pesan', DB::raw('SUM(detail_pemesanan.jumlah)'))
->groupBy('pemesanan.tgl_pesan')
->get();
And this is my operation
for ($i = 0; $i < 6; $i++) {
if ($i == 0) {
$st[$i] = $data[$i]->jumlah;
$bt[$i] = $data[$i + 1]->jumlah - $data[$i]->jumlah;
$ftm[$i] = null;
$pe[$i] = null;
} else {
$st[$i] = $alpha * $data[$i]->jumlah + (1 - $alpha) * ($st[$i - 1] + $bt[$i - 1]);
$bt[$i] = $gamma * ($st[$i] - $st[$i - 1]) + (1 - $gamma) * $bt[$i - 1];
$ftm[$i] = ($st[$i - 1] + $bt[$i - 1]) * 1;
$pe[$i] = (($data[$i]->jumlah - $ftm[$i]) / $data[$i]->jumlah) * 100;
}
if ($pe[$i] < 0) {
$pe[$i] = abs($pe[$i]);
}
}
Any solution? Thanks