php分页原理

<?php
/*
 * 分页实现
 */
include("conn.php");
$pagesize=2;
$url=$_SERVER["REQUEST_URI"];
$url=parse_url($url);
$url=$url[path];
$numq=mysql_query("SELECT * from test");
$num=mysql_num_rows($numq);
if($_GET[page]){
    $pageval=$_GET[page];
    $page=($pageval-1)*pagesize;
    $page.=',';
}
if($num > $pagesize) {
    if($pageval<=0)$pageval=1;
    echo"共 $num 条"."<a href=$url?page=".($pageval-1).">上一页</a><a href=$url?page=".($pageval+1).">下一页</a>";
}
 $SQL="SELECT * from test limit $page $pagesize";
 $query=mysql_query($SQL);
 while($row=mysql_fetch_array($query)){
     echo"<hr><b>".$row[name]." |".$row[sex];
 }
?>