Error when update mahasiswa

[Uniclowns]

i use protected $primaryKey = 'NIM';
public $incrementing = false;
protected $keyType = 'string';
(IN Mahasiswa Model)

it's already fine when store/add data to database but when i want to update the data, it's alwasys error.

[fasaya]

On the controller you received model as a parameter Mahasiswa $mahasiswa which by default will look for the data by id (which you don't have) that is why you're getting Unknown column id error.

On resources/views/mahasiswa/edit.blade.php you pass $mahasiswa->NIM, so you could change your update method on your controller as:

    public function update(Request $request, $mahasiswa) : RedirectResponse
    {
        $mahasiswa = Mahasiswa::where('NIM', $mahasiswa)->findOrFail();

        $firstData = [
            'NIM' => 'required|string|max:16|unique:mahasiswas,NIM,' . $mahasiswa->NIM,
            'nama' => 'required|string|max:250',
            'jurusan' => 'required|string|max:255',
            'prodi' => 'required|string|max:255',
            'alamat' => 'required|string|max:255',
            'ttl' => 'required|string|max:255',
            'no_hp' => 'required|string|max:255',
        ];

        $validated = $request->validate($firstData);

        $mahasiswa->update($request->all());
        return redirect()->route('mahasiswas.index')->withSuccess('Data Mahasiswa is updated successfully');
    }