<?php
$conn = new mysqli("localhost", "root", "", "gis_spbu");

$id = $_POST['id'];
$nama = $_POST['nama'];
$wa = $_POST['wa'];
$buka = $_POST['buka'];

$conn->query("UPDATE spbu SET 
    nama='$nama',
    wa='$wa',
    buka='$buka'
WHERE id='$id'");
?>