index.php

<?php
    include("koneksi.php");
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <link rel="stylesheet" href="index.css" />
    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
    <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">

    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css">

    <!-- Compiled and minified JavaScript -->
    <script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
    <title>Document</title>
</head>
<body class="parent-body" >
     <div class="body" >
        <div class="row children-body"  >
    <form class="col s12" action="" method="post" >

      <div class="row">
      <div class="input-field col s6">
          <input name="nama_pendaftar" type="text" class="validate">
          <label for="last_name">Nama Pendaftar</label>
        </div>
        <div class="input-field col s6">
          <input name="tempat_lahirr" type="text" class="validate">
          <label for="last_name">Tempat Lahir</label>
        </div>
    </div>
    <div class="row">
      <div class="input-field col s6">
      <!-- <label for="datepicker">tanggal lahir</label>
      <input name="tanggal_lahir" type="text" class="datepicker">
        <script>
         document.addEventListener('DOMContentLoaded', function() {
    var elems = document.querySelectorAll('.datepicker');
    var instances = M.Datepicker.init(elems, options);
  });

  // Or with jQuery

  $(document).ready(function(){
    $('.datepicker').datepicker();
  });

        </script> -->
        </div>
        <div class="input-field col s6">
          <input name="alamat" type="text" class="validate">
          <label for="last_name">Alamat</label>
        </div>
    </div>
    <div class="row">
      <div class="input-field col s6">
          <input name="kecamatan" type="text" class="validate">
          <label for="last_name">Kecamatan</label>
        </div>
        <div class="input-field col s6">
          <input name="kabupaten" type="text" class="validate">
          <label for="last_name">Kabupaten</label>
        </div>
    </div> <div class="row">
      <div class="input-field col s6">
          <input name="provinsi" type="text" class="validate">
          <label for="last_name">provinsi</label>
        </div>
        <div class="input-field col s6">
          <input name="kode_pos" type="text" class="validate">
          <label for="last_name">kode pos</label>
        </div>
    </div>
    <div class="row">

        <div class="input-field col s6">
          <input name="asal_sekolah" type="text" class="validate">
          <label for="last_name">Asal Sekolah</label>
        </div>
    </div>

     <div class="row header" >
     <button type="submit" name='tambah' class="btn btn-warning">SUBMIT</button>

    </div>

      </div>
    </form>
  </div>

     </div>
</body>
</html>

<?php

$koneksi = mysqli_connect('localhost','talenta','talenta123','tugas');

    if(!empty('nama_pendaftar'))

    {
      $nama_pendaftar = $_REQUEST['nama_pendaftar'];
      $tempat_lahir = $_REQUEST['tempat_lahir'];
      // $tanggal_lahir = $_POST['tanggal_lahir'];
      $alamat = $_REQUEST['alamat'];
      $kecamatan = $_REQUEST['kecamatan'];
      $kabupaten = $_REQUEST['kabupaten'];
      $provinsi = $_REQUEST['provinsi'];
      $kode_pos = $_REQUEST['kode_pos'];
      $asal_sekolah = $_REQUEST['asal_sekolah'];

      $sqltambah = mysqli_query($koneksi,"INSERT INTO table_pendaftaran(nama_pendaftar,tempat_lahir,alamat,kecamatan,kabupaten,provinsi,kode_pos,asal_sekolah) VALUES('$nama_pendaftar','$tempat_lahir','$alamat','$kecamatan','$kabupaten','$provinsi','$kode_pos','$asal_sekolah')");
      if($sqltambah){
        echo '<script>alert("Berhasil di Tambahkan")</script>';
        echo '<meta http-equiv="refresh" content="0">';
      }
      else{
        echo '<script>alert("gagal di Tambahkan")</script>';
        // echo '<meta http-equiv="refresh" content="0">';
      }
    }
?>