php处理分页数据并返回json

<?php
header('content-type:application/json;charset=utf-8');//设置浏览器解析格式为json
header('Access-Control-Allow-Origin: *');
$curPage = $_GET['page'];//前台传递的当前页
$pageSize = 20;//页容量大小
$start = ($curPage - 1) * $pageSize;//起始页数
$totalPage = 0;//总页数
$conn = mysqli_connect("localhost", "root", "root","s");//数据库连接参数
$pageList = array();//用来封装分页数据的数组
	
//执行分页查询的同时在数据库中设置一个新字段，总记录数
$sql="SELECT * ,(select count(*) FROM s) as total from s limit $start,$pageSize";
$result = mysqli_query($conn, $sql);
	
while ($row = mysqli_fetch_assoc($result)) {
	$items = array(
		"itemid" => $row['itemid'],
		"itemtitle" => $row['itemtitle'],
	    "image" => $row['itempic'],
	    "price" => $row['orderfee']//
	    );
	    //总页数等于总记录数/页容量，向上取整, 如3.5页，要有第四页
	    $totalPage = ceil($row['total'] / $pageSize);
	    array_push($pageList, $items);//填充分页数据
	}
mysqli_close($conn);//关闭连接
echo json_encode($pageList,JSON_UNESCAPED_UNICODE);
?>