PHP如何实现网页分页效果
在PHP网站之说，有很多需要实现分页效果，主要是用于阅读小说。
功能实现如下：
使用sql查询进行分页时，需要调用几个函数，具体见脚本：
1.pager.class.php
<?php
class pager {
public $sql; //SQL查询语句
public $datanum; //查询所有的数据总记录数
public $page_size; //每页显示记录的条数
protected $_errstr;
protected $_conn;
protected $_query_id;
public function query($query)///这个函数有问题，暂时可以不用
{
$ret = false;
if (!empty($query)) {
if ($this->_conn === false || !is_resource($this->_conn)) {
warningLog(__METHOD__ . ': query sql with no connection', true);
return false;
}
$this->_query_id = @mysql_query($query, $this->_conn);
if ($this->_query_id === false) {
$this->_errstr = @mysql_error();
$ret = false;
} else {
$this->_errstr = 'SUCCESS';
$ret = $this->_query_id;
}
}
$msg = ($ret === false) ? 'false' : strval($ret);
debugLog(__METHOD__.": [$msg] returned for sql query [$query]");
return $ret;
}
function __construct($sql,$page_size) {
$result = mysql_query($sql);
$datanum = mysql_num_rows($result);
$this->sql=$sql;
$this->datanum=$datanum;
$this->page_size=$page_size;
}
//当前页数
public function page_id() {
if($_SERVER['QUERY_STRING'] == ""){
return 1;
}elseif(substr_count($_SERVER['QUERY_STRING'],"page_id=") == 0){
return 1;
}else{
return intval(substr($_SERVER['QUERY_STRING'],8));
}
}
//剩余url值
public function url() {
if($_SERVER['QUERY_STRING'] == ""){
return "";
}elseif(substr_count($_SERVER['QUERY_STRING'],"page_id=") == 0){
return "&".$_SERVER['QUERY_STRING'];
}else{
return str_replace("page_id=".$this->page_id(),"",$_SERVER['QUERY_STRING']);
}
}
//总页数
public function page_num() {
if($this->datanum == 0){
return 1;
}else{
return ceil($this->datanum/$this->page_size);
}
}
//数据库查询的偏移量
public function start() {
return ($this->page_id()-1)*$this->page_size;
}
//数据输出
public function sqlquery() {
return $this->sql." limit ".$this->start().",".$this->page_size;
}
//获取当前文件名
private function php_self() {
return $_SERVER['PHP_SELF'];
}
//上一页
private function pre_page() {
if ($this->page_id() == 1) { //页数等于1
return "<a href=".$this->php_self()."?page_id=1".$this->url().">上一页</a> ";
}elseif ($this->page_id() != 1) { //页数不等于1
return "<a href=".$this->php_self()."?page_id=".($this->page_id()-1).$this->url().">上一页</a> ";
}
}
//显示分页
private function display_page() {
$display_page = "";
if($this->page_num() <= 10){ //小于10页
for ($i=1;$i<=$this->page_num();$i++) //循环显示出页面
$display_page .= "<a href=".$this->php_self()."?page_id=".$i.$this->url().">".$i."</a> ";
return $display_page;
}elseif($this->page_num() > 10){ //大于10页
if($this->page_id() <= 6){
for ($i=1;$i<=10;$i++) //循环显示出页面
$display_page .= "<a href=".$this->php_self()."?page_id=".$i.$this->url().">".$i."</a> ";
return $display_page;
}elseif(($this->page_id() > 6) && ($this->page_num()-$this->page_id() >= 4)){
for ($i=$this->page_id()-5;$i<=$this->page_id()+4;$i++) //循环显示出页面
$display_page .= "<a href=".$this->php_self()."?page_id=".$i.$this->url().">".$i."</a> ";
return $display_page;
}elseif(($this->page_id() > 6) && ($this->page_num()-$this->page_id() < 4)){
for ($i=$this->page_num()-9;$i<=$this->page_num();$i++) //循环显示出页面
$display_page .= "<a href=".$this->php_self()."?page_id=".$i.$this->url().">".$i."</a> ";
return $display_page;
}
}
}
//下一页
private function next_page() {
if ($this->page_id() < $this->page_num()) { //页数小于总页数
return "<a href=".$this->php_self()."?page_id=".($this->page_id()+1).$this->url().">下一页</a> ";
}elseif ($this->page_id() == $this->page_num()) { //页数等于总页数
return "<a href=".$this->php_self()."?page_id=".$this->page_num().$this->url().">下一页</a> ";
}
}
// 设置分页信息
public function set_page_info() {
$page_info = "共".$this->datanum."条 ";
$page_info .= "<a href=".$this->php_self()."?page_id=1".$this->url().">首页</a> ";
$page_info .= $this->pre_page();
$page_info .= $this->display_page();
$page_info .= $this->next_page();
$page_info .= "<a href=".$this->php_self()."?page_id=".$this->page_num().$this->url().">尾页</a> ";
$page_info .= "第".$this->page_id()."/".$this->page_num()."页";
return $page_info;
}
}
?>
2.脚本2：
<?php
//类的用法
// 读取分页类
include("pager.class.php");
// 数据库连接初始化
// $db = new mysql();
$impeach_host = '10.81.43.139';
$impeach_usr = 'vmtest15';
$impeach_passwd = 'vmtest15';
$impeach_name = 'ufeature';
$impeach_con = mysql_connect($impeach_host, $impeach_usr, $impeach_passwd) or
die("Can't connect ".mysql_error());
mysql_select_db($impeach_name, $impeach_con);
// 这是一个sql查询语句，并得到查询结果
$sql = "select word from ufeature.spam_accuse_word_list where flag='0'";
// 分页初始化
$page = new pager($sql,20);
// 20是每页显示的数量
// $res_1 = mysql_query($sql) or
// die("Can't get result ".mysql_error());
$result=mysql_query($page->sqlquery());
while($info = mysql_fetch_array($result,MYSQL_ASSOC)){
// while($info = mysql_fetch_array($res_1, MYSQL_ASSOC)){
echo $info["word"]."<br/>";
}
// 页码索引条
echo $page->set_page_info();
?>
二，使用ajax的方法
1、首先了解SQL语句中的limit用法
例子：
取前20条记录：SELECT * FROM table …… limit 0 ， 20
从第11条开始取20条记录：SELECT * FROM table …… limit 10 ， 20
LIMIT n 等价于 LIMIT 0,n。
如select * from table LIMIT 5; //返回前5行,和 select * from table LIMIT 0，5一样
2、分页原理
所谓分页显示，也就是讲数据库中的结果集，一段一段显示出来
第11至20条记录：select * from table limit 10,10
第21至30条记录：select * from table limit 20,10
Select * from table limit ($Page- 1) * $PageSize, $PageSize
3、$_SERVER["REQUEST_URI"]函数
预定义服务器变量的一种，所有$_SERVER开头的都叫做预定于服务器变量。
REQUEST_URI的作用是取得当前URI，也就除域名外后面的完整的地址路径。
例子：
当前页为：http://www.test.com/home.php?id=23&cid=22
echo $_SERVER["REQUEST_URI"]
结果为：/home.php?id=23&cid=22
$ua=parse_url("http://username:password@hostname/path?arg=value#anchor");
print_r($ua);
结果：
(
[scheme] => http ；协议
[host] => hostname ；主机域名
[pass] => password ；密码
[path] => /path ；路径
[query] => arg=value ；取参数
)
mysql_select_db("bbs", $conn);
mysql_query("set names 'GBK'"); //使用GBK中文编码;
$content = str_replace("\n", "<br>", str_replace(" ", " ", $content)); //两个str_replace嵌套
}
//htmlspecialchars();
include("conn.php");
$url=$_SERVER["REQUEST_URI"];
$url=parse_url($url);
$url=$url[path];
$numq=mysql_query("SELECT * FROM `message`");
$num = mysql_num_rows($numq);
$pageval=$_GET[page];
$page=($pageval-1)*$pagesize;
$page.=',';
}
if($num > $pagesize){
if($pageval<=1)$pageval=1;
" <a href=$url?page=".($pageval-1).">上一页</a> <a href=$url?page=".($pageval+1).">下一页</a>";
}
$SQL="SELECT * FROM `message` limit $page $pagesize ";
$query=mysql_query($SQL);
while($row=mysql_fetch_array($query)){
?>
<tr bgcolor="#eff3ff">
<td>标题：<?php echo $row[title]?></td> <td>时间：<?php echo $row[lastdate]?></td>
</tr>
<tr bgcolor="#eff3ff">
<td> 用户：<?php echo $row[user]?></td><td></td>
</tr>
<tr>
<td>内容：<?php echo htmtocode($row[content]);?></td>
</tr>
<br>
</table>
}
?>
（4）最后显示
方法3：
<script>
function viewpage(p){
if(window.XMLHttpRequest){
var xmlReq = new XMLHttpRequest();
} else if(window.ActiveXObject) {
var xmlReq = new ActiveXObject('Microsoft.XMLHTTP');
}
var formData = "page="+p;
xmlReq.onreadystatechange = function(){
if(xmlReq.readyState == 4){
document.getElementByIdx_x('content2').innerHTML = xmlReq.responseText;
}
}
xmlReq.open("post", "hotel_list.php", true);
xmlReq.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlReq.send(formData);
return false;
}
</script>
脚本2：
header("Content-Type:text/html;charset=GB2312");
$pagesize=10;
//echo $_POST['page'];
$result = mysql_query("Select count(DISTINCT hotelname) FROM ".TBL_HOTELS);
$myrow = mysql_fetch_array($result);
$numrows=$myrow[0];
$pages=intval($numrows/$pagesize);
if ($numrows%$pagesize)
$pages++;
if (isset($_POST['page'])){
$page=intval($_POST['page']);
}
else{
//设置为第一页
$page=1;
}
$first=1;
$prev=$page-1;
$next=$page+1;
$last=$pages;
//计算记录偏移量
$offset=$pagesize*($page - 1);
//读取指定记录数
$result=mysql_query("select `hotelname` , count( * ) from ".TBL_HOTELS." GROUP BY `hotelname` order by id desc limit $offset,$pagesize");
$num = mysql_num_rows($result);
while ($row = mysql_fetch_array($result,MYSQL_NUM)) {
$hotelname[] = $row[0];
$countpeople[] = $row[1];
}
for($a=0;$a<$num;$a++)
{
//$result=mysql_query("select count(title) from " . TBL_Comments ." where `title`=\"".$title[$a]."\"");
//$row = mysql_fetch_row($result);
echo "<TABLE style=\"MARGIN-BOTTOM: 20px\" cellSpacing=0 cellPadding=0 width=100% border=0>\n";
echo "<TBODY>\n";
echo "<TR>\n";
echo "<TD style=\"PADDING-TOP: 5px\" vAlign=top align=left width=80>\n";
//rating_bar($title[$a],5);
echo "</TD>\n";
echo "<TD style=\"PADDING-TOP: 5px\" align=left width=100%><A title=$hotelname[$a] style=\"FONT-SIZE: 14px\" href=#>$hotelname[$a]</A>\n";
echo "</TD></TR>\n";
echo " <TR>\n";
echo "<TD></TD>\n";
echo "<TD style=\"PADDING-LEFT: 0px\">\n";
echo "<IMG src=\"images/comment.gif\" border=0> 推荐人数:($countpeople[$a]) |\n";
echo "<SPAN>平均分：<STRONG></STRONG> (".$count."票) | 评论数:()</SPAN>\n";
echo "</TD></TR></TBODY></TABLE>\n";
}
echo "<TABLE style=\"MARGIN-TOP: 30px\" cellSpacing=0 cellPadding=0 width=\"100%\"";
echo "border=0>";
echo "<TBODY><TR><TD colSpan=3 height=20>";
echo "<DIV align=center>";
echo "<P align=left><FONT color=red>第".$page."页/总".$pages."页 | 总".$numrows."条</FONT> | ";
if ($page>1) echo "<a onclick=\"viewpage(".$first.")\" href='#'>首页</a> | ";
if ($page>1) echo "<a onclick=\"viewpage(".$prev.")\" href='#'>上页</a> | ";
if ($page<$pages) echo "<a onclick=\"viewpage(".$next.")\" href='#'>下页</a> | ";
if ($page<$pages) echo "<a onclick=\"viewpage(".$last.")\" href='#'>尾页</a>";
echo "转到第 <INPUT maxLength=3 size=3 value=1 name=goto_page> 页 <INPUT hideFocus onclick=\"viewpage(document.all.goto_page.value)\" type=button value=Go name=cmd_goto>";
echo "</P></DIV></TD></TR></TBODY></TABLE>";