how to check if data already exist when insert data - php

Question

I want to ask how to to check the data if we input data if there is the same data that cannot be inserted.
My code:
$obj = new Pengajuan();
// $obj->id_pengajuan = $req->input('kode');
$obj->id_nasabah = $req->input('id_nasabah');
$obj->tgl_pengajuan = $req->input('tgl_pengajuan');
$obj->besar_pinjaman = $req->input('besar_pinjaman');
$obj->status = $req->input('status');
$simpan = $obj->save();
if ($simpan == 1) {
$status = "Tersmpan";
} else {
$status = "Gagal";
}
echo json_encode(array("status" => $status));

Answer 1

Above of the code add a validation like below:
$this->validate([
'id_nasabah' =>'unique:pengajuans'
]) ;
And then rest of your controller code.

Answer 2

try this:
public function store(Request $request)
{
$this->validate($request,[
'id_nasabah'=>'required|exists:your_table_name,id',
'tgl_pengajuan'=>'more_validations',
'besar_pinjaman'=>'more_validations',
]);
//if $this->validate() fails, it will return a response 422 code error
//else it will continue with the creation of your object
//is a good idea to use a try-catch in case of something goes wrong
try
{
$pengajuan=Pengajuan::create($request->only('id_nasabah','tgl_pengajuan','besar_pinjaman'));
return response->json([
'pengajuan'=>$pengajuan,
'status'=>'Tersmpan',
],200);//return a http code 200 ok
}
catch(Exception $e)
{
//'message'=>'this will return what is the error and line'
return response()->json([
'message'=>$e->getMessage().'/'.$e->getLine(),
'status'=>'Gagal',
],422);
}
}