How to properly Update in the papers and authors table - php

Question

I have a problem that whenever I update a paper it will always error out Unknown variable [Fname]
This is the update function in my controller
public function update(Request $request, $PaperID)
{
$request->validate([
'PaperTitle' => 'required',
'PaperType' => 'required',
'file' => [
'required',
File::types('pdf')
->max(12 * 1024),
],
]);
$paper=Papers::find($PaperID);
$file=$request->file;
$filename=time().'.'.$file->getClientOriginalExtension();
$request->file->move('assets', $filename);
$paper->file=$filename;
$paper->PaperTitle=$request->PaperTitle;
$paper->PaperType=$request->PaperType;
$paper->College=$request->College;
$paper->DateCompleted=$request->DateCompleted;
$paper->ContentAdviser=$request->ContentAdviser;
$paper->update();
$input = $request->all();
if(count($input['Fname']) > 0){
for($i = 0 ; $i < count($input['Fname']) ; $i++){
$author->Fname = $input['Fname'][$i];
$author->Lname = $input['Lname'][$i];
$author->update();
}
}
return redirect()->back()->with('success','File has been updated.');
}
the storing works fine but update doesn't how to fix this? I want that both papers and authors table will update the papers updates fine but the author does not

Answer 1

Solution
Use $paper->save() — update expects different params.
Try this for updating:
$paper->update($request->validated()->except('file'))
// or
`$paper->update($request->validated()->only(['field1', 'field2', 'etc'))`
(of course, you'll want to add validation for all Model attributes)
Extra credit (PR Review Learning Comments)
1. Code Readability
First, add spaces around your = & after your if's. Better yet, use a library (like php-cs-fixer) to automatically format your code.
2. Use a custom UpdatePaperRequest
Using a custom Request rather than using $request->validate() helps organize your code. Laravel delegates validation to requests. You can then test the Request separately, create reusable/shared functionality (Traits/Concernst), etc... it's just better trust me :)