jQueryのAjaxでリアルタイム検索のやつ #PHP

ありがちなやつです。
備忘録的な感じで書いてます。

index.html

<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>Welcome!</title>
</head>
<body>

<h1>Search our Phone Directory</h1>
<form id="searchform" method="post">
<div>
    <label for="search_term">Search name/phone</label>
    <input type="text" name="search_term" id="search_term" />
    <input type="submit" value="search" id="search_button" />
    </div>
</form>
<div id="search_results"></div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script type='text/javascript'>
$(document).ready(function(){
$("#search_results").slideUp();
    $("#search_button").click(function(e){
        e.preventDefault();
        ajax_search();
    });
    $("#search_term").keyup(function(e){
            e.preventDefault();
            ajax_search();
        });

});
function ajax_search(){
  $("#search_results").show();
  var search_val=$("#search_term").val();
  $.post("./find.php", {search_term : search_val}, function(data){
   if (data.length>0){
     $("#search_results").html(data);
   }
  })
}
</script>
</body>
</html>

find.php

<?php
define(HOST, "xxx");
define(USER, "xxx");
define(PW, "xxxx");
define(DB, "xxx");

$connect = mysqli_connect(HOST,USER,PW) or die('Could not connect to mysql server.' );
mysqli_select_db($connect,DB) or die('Could not select database.');
mysqli_set_charset($connect, "utf8");

$term = strip_tags(substr($_POST['search_term'],0, 100));
$term = mysqli_real_escape_string($connect,$term);

$sql = "SELECT member_name,member_phone FROM members where member_name like '%$term%' or member_phone like '%$term%' order by member_name asc";
$result = mysqli_query($connect,$sql);

$string = '';

if(mysqli_num_rows($result) > 0){
  while($row = mysqli_fetch_assoc($result)){
    $string .= $row['member_name']." - ";
    $string .= $row['member_phone'];
    $string .= "<br/>\n";
  }

}else{
  $string = "No matches!";
} 

echo $string;

簡単ではありますが、こんなもんで勘弁して下さい。