laravel Maatwebsite validate sum multi column - laravel

Question

hi im using Maatwebsite with laravel everything working so good so far ..
but i want to update excel like this ..
number date amount
1 2020-01-01 10
1 2020-01-01 -5
1 2020-01-01 -5
2 2020-02-02 20
2 2020-02-02 -20
3 2020-03-03 50
3 2020-03-03 -50
3 2020-03-03 40
3 2020-03-03 -40
what i want thats the sum of the amount with number 1 sould return 0 or end the import
number date amount
1 2020-01-01 10
1 2020-01-01 -5
1 2020-01-01 -5
how can i check this (10 + -5 + -5 == 0) or fail
and for 2 and 3 ect ..
thanks a lot

Answer 1

I explained all the steps in comments but I will explain here as well.
When you loop through each row, you first need to grab all the rows where number field is 1, 2 or 3, what ever the number is currently in the iteration.
In this case, the first loop results will be:
number date amount
1 2020-01-01 10
1 2020-01-01 -5
1 2020-01-01 -5
Then you sum (add up) the values from the amount column.
In this case, it will sum like this:
10
-5
-5
-----
0
If the answer is not 0, take the current sheet ($sheet) and return what you currently have, to be exported.
Full class:
...
use Maatwebsite\Excel\Concerns\FromArray;
class ExampleExport implements FromArray
{
public function array() : array
{
// EXAMPLE hardcoded data for the purpose of this demo
$rows = [
[
'number' => 1,
'date' => '2020-01-01',
'amount' => 10
],
[
'number' => 1,
'date' => '2020-01-01',
'amount' => -5
],
[
'number' => 1,
'date' => '2020-01-01',
'amount' => -5
],
[
'number' => 2,
'date' => '2020-02-02',
'amount' => 20
],
[
'number' => 2,
'date' => '2020-02-02',
'amount' => -20 // <-------- Change this to -21 to test
],
[
'number' => 3,
'date' => '2020-03-03',
'amount' => 50
],
[
'number' => 3,
'date' => '2020-03-03',
'amount' => -50
],
[
'number' => 3,
'date' => '2020-03-03',
'amount' => 40
],
[
'number' => 3,
'date' => '2020-03-03',
'amount' => -40
],
];
// EXAMPLE hardcoded data for the purpose of this demo
$rows = collect($rows);
// You probably going to get this from your database so should look like this:
// $rows = \App\Model::all(['number', 'date', 'amount']); // OR below
// $rows = DB::table('examples')->select(['number', 'date', 'amount'])->get();
// Blank sheet
$sheet = [];
foreach ($rows as $row) {
// Get all the rows where the `number` field has the same value,
// for example 1, 2, or 3, then sum the `amount` field (add up).
//
// If the amount does not add up to 0, stop and return what you currently got
if ($rows->where('number', $row['number'])->sum('amount') !== 0) {
return $sheet;
}
// Else, add them to the sheet and continue.
$sheet[] = $row;
}
return $sheet;
}
}
Results:
When amount adds up to 0:
When amount does not add up to 0: