Laravel multiple data insert into database - arrays

Question

i want to insert more items to one delivery_notes_id in Laravel. But i get the error "Array to String conversion". When i delete the code with $lastid then is no error.
Can you help me?
$data=$request->all();
$lastid=delivery_note::create($data)->id;
$delivery_note->datum = $data['datum'];
$delivery_note->customer_id = $data['customer'];
if(count($data['produkt']) > 0)
{
$data2=[];
foreach($data['produkt'] as $item => $value)
array_push($data2, [
'delivery_notes_id'=>$lastid,
'menge'=>$request['menge'][$item],
'einheit'=>$request['einheit'][$item],
'product_id'=>$request['produkt'][$item],
]);
Items::insert($data2);
}
return $this->index()->with([
'meldung_success' => 'Lieferschein wurde erstellt!'
]);
}
Here is the HTML Code. I've tried this with the following tutorial https://tsdurjoy.blogspot.com/2019/01/laravel-multiple-data-insert-into_20.html
<div class="container">
<div class="row justify-content-center">
<div class="col-md-12">
<div class="container">
<h4 class="text-center"><i class="fas fa-chevron-left"></i> neuer LIEFERSCHEIN</h4>
<form class="row g-3" action="/delivery_note" method="post">
#csrf
<table>
<tbody>
<tr>
<label for="datum" class="form-label">Datum</label>
<input type="date" class="form-control" name="datum" id="datum" value="{{ old('datum') }}">
</tr>
<tr>
<label for="customer_id" class="form-label">Kunde</label>
<select id="customer_id" class="form-control" name="customer">
<option selected>Kunde wählen</option>
#foreach (App\Customer::get() as $customers)
<option value="{{$customers->id}} ">{!! $customers->customer !!}</option>
#endforeach
</select>
</tr>
<div id="more">
<tr>
<td>
<label for="menge" class="form-label">Menge</label>
<input type="text" class="form-control" name="menge[]" id="menge" value="{{ old('menge') }}">
</td>
<td>
<label for="einheit" class="form-label">EH</label>
<input type="text" class="form-control" name="einheit[]" id="einheit" value="{{ old('einheit') }}">
</td>
<td>
<label for="produkt" class="form-label">Produkt</label>
<select id="produkt" class="form-control" name="produkt[]">
<option selected>Produkt wählen</option>
#foreach (App\Product::get() as $produkt)
<option value="{{$produkt->id}}">{!! $produkt->produkt !!}</option>
#endforeach
</select>
</td>
</tr>
</div>
</tbody>
</table>
<div class="col-12 mt-2">
<a class="addRow" name="addRow" id="addRow">+ weiteres Produkt</a>
</div>
<div class="col-12 mt-4">
<button type="submit" class="btn btn-primary">SPEICHERN</button>
</div>
</form>
</div>
</div>
</div>
<script type="text/javascript">
$('.addRow').on('click', function() {
addRow();
});
function addRow() {
var tr = '<tr>'+
'<td>'+
'<input type="text" class="form-control" name="menge[]" id="menge" value="{{ old('menge') }}">'+
'</td>'+
'<td>'+
'<input type="text" class="form-control" name="einheit[]" id="einheit" value="{{ old('einheit') }}">'+
'</td>'+
'<td>'+
'<select id="produkt" class="form-control" name="produkt[]">'+
'<option selected>Produkt wählen</option>'+
'#foreach (App\Product::get() as $produkt)'+
'<option value="{{$produkt->id}}">{!! $produkt->produkt !!}</option>'+
'#endforeach'+
'</select>'+
'</td>'+
'</tr>';
$('tbody').append(tr);
};
</script>

Answer 1

try like this one:
$data=$request->all();
$lastid=delivery_note::create($data)->id;
$delivery_note->datum = $data['datum'];
$delivery_note->customer_id = $data['customer'];
if(count($data['produkt']) > 0)
{
foreach($requsest->get('produkt') as $item => $value){
$data = new yourModelName();
$data->delivery_notes_id=$lastid;
$data->menge=$request->menge[$item];
$data->einheit=$request->einheit[$item];
$data->product_id=$request->produkt[$item]
$data->save();
}
}
return $this->index()->with([
'meldung_success' => 'Lieferschein wurde erstellt!'
]);
}