Laravel duplicate entries when reload page - php

Question

I have a model ,a controller and a form for introducing entries to database.The problem is that refresing the page cause duplicate entries in database.How to resolv it?
loan.controller:
public function store(Request $request)
{ $id = Auth::id();
$loan=New loan;
$loan->cod_user=$id;
$loan->nume =$request->name;
$loan->data=$request->date;
$loan->durata=$request->period;
$loan->valoare_rata_luna=$request->month;
$loan->valoare_totala=$request->amount;
$loan->save();
return view('loans');
}
the form from loans view:
<div class="container">
<div class="row">
<div class="col-md-4">
<div class="blacktext"><h3>My Loans:</h3></div>
</div>
<div class="col-md-4"></div>
<div class="col-md-2"></div>
<div class="col-md-2"><button type="button" class="btn btn-success" data-toggle="modal" data-target="#modal1">
<span class="glyphicon glyphicon-plus-sign"></span> Add Loan</button></div>
<div class="modal fade " id="modal1" role="dialog">
<div class="modal-dialog modal-lg">
<div class="modal-content">
<div class="modal-header">
<button class="close" data-dismiss="modal">×</button>
<h3>Add Loan</h3>
</div>
<div class="modal-body text-right">
<form action="{{ route('loan.store') }}" method="POST">
<p class="al-left">
{{csrf_field()}}
<label for="date">Date:</label>
<input type = "date" name="date" placeholder="Date" id="date">
</p>
...
<p class="al-left">
<label for="amount">Amount:</label>
<input type = "number" name="amount" placeholder="0" id="amount">
</p>
<input type="submit" class="btn btn-sm btn-primary" name="submit" value="Add">

Answer 1

Just redirect to the route (the route which serves the view) instead of the view at the end of your store method:
public function store(Request $request)
{ $id = Auth::id();
$loan=New loan;
$loan->cod_user=$id;
$loan->nume =$request->name;
$loan->data=$request->date;
$loan->durata=$request->period;
$loan->valoare_rata_luna=$request->month;
$loan->valoare_totala=$request->amount;
$loan->save();
return redirect(route(('loans')); //asumming that you named a route as loans
}

Answer 2

Try to use
return redirect()-back();
It will work for sure.

Answer 3

POST still exists upon refresh .. what you can do is have a page separated from store function .. like this ..
ROUTE
Route::get('/loans', 'LoanController#viewLoanForm');
Route::post('/loans', 'LoanController#store');
LoanController
public function viewLoanForm()
{
return view('loan');
}
public function store(Request $request)
{
// process your input
return redirect('/loans');
}

Answer 4

I think you should change your return method like:
public function store(Request $request)
{ $id = Auth::id();
$loan=New loan;
$loan->cod_user=$id;
$loan->nume =$request->name;
$loan->data=$request->date;
$loan->durata=$request->period;
$loan->valoare_rata_luna=$request->month;
$loan->valoare_totala=$request->amount;
$loan->save();
return redirect()->route('loans');
}