<?php
/*
 * 使用:
 * $page = new Page(连接符,查询语句,当前页码,每页大小,页码符)
 * 连接符:一个MYSQL连接标识符,如果该参数留空,则使用最近一个连接
 * 查询语句:SQL语句
 * 当前页码:指定当前是第几页
 * 每页大小:每页显示的记录数
 * 页码符:指定当前页面URL格式
 *
 * 使用例子:
 * $sql = "select * from aa";
 * $page = new Page($conn,$sql,$_GET['page'],4,"?page=");
 *
 * 获得当前页码
 * $page->page;
 *
 * 获得总页数
 * $page->pageCount;
 *
 * 获得总记录数
 * $page->rowCount;
 *
 * 获得本页记录数
 * $page->listSize;
 *
 * 获得记录集
 * $page->list;
 * 记录集是一个2维数组,例:list[0]['id']访问第一条记录的id字段值.
 *
 * 获得页码列表
 * $page->getPageList();
 */
class Page
{
 //基础数据
 var $sql;
 var $page;
 var $pageSize;
 var $pageStr;
 //统计数据
 var $pageCount; //页数
 var $rowCount; //记录数
 //结果数据
 var $list = array(); //结果行数组
 var $listSize ;
 //构造函数
 function Page($conn,$sql_in,$page_in,$pageSize_in,$pageStr_in)
 {
  $this->sql = $sql_in;
  $this->page = intval($page_in);
  $this->pageSize = $pageSize_in;
  $this->pageStr = $pageStr_in;
  //页码为空或小于1的处理
  if(!$this->page||$this->page<1)
  {
   $this->page = 1;
  }
  //查询总记录数
  $rowCountSql = preg_replace("/([\w\W]*?select)([\w\W]*?)(from[\w\W]*?)/i","$1 count(0) $3",$this->sql);
  if(!$conn)
   $rs = mysql_query($rowCountSql) or die("bnc.page: error on getting rowCount.");
  else
   $rs = mysql_query($rowCountSql,$conn) or die("bnc.page: error on getting rowCount.");
  $rowCountRow = mysql_fetch_row($rs);
  $this->rowCount=$rowCountRow[0];
  //计算总页数
  if($this->rowCount%$this->pageSize==0)
   $this->pageCount = intval($this->rowCount/$this->pageSize);
  else
   $this->pageCount = intval($this->rowCount/$this->pageSize)+1;
  //SQL偏移量
  $offset = ($this->page-1)*$this->pageSize;
  if(!$conn)
   $rs = mysql_query($this->sql." limit $offset,".$this->pageSize) or die("bnc.page: error on listing.");
  else
   $rs = mysql_query($this->sql." limit $offset,".$this->pageSize,$conn) or die("bnc.page: error on listing.");
  while($row=mysql_fetch_array($rs))
  {
   $this->list[]=$row;
  }
  $this->listSize = count($this->list);
 }
 /*
  * getPageList方法生成一个较简单的页码列表
  * 如果需要定制页码列表,可以修改这里的代码,或者使用总页数/总记录数等信息进行计算生成.
  */
 function getPageList()
 {
  $firstPage;
  $previousPage;
  $pageList;
  $nextPage;
  $lastPage;
  $currentPage;
  //如果页码>1则显示首页连接
  if($this->page>1)
  {
   $firstPage = "<a href=\"".$this->pageStr."1\">首页</a>";
  }
  //如果页码>1则显示上一页连接
  if($this->page>1)
  {
   $previousPage = "<a href=\"".$this->pageStr.($this->page-1)."\">上一页</a>";
  }
  //如果没到尾页则显示下一页连接
  if($this->page<$this->pageCount)
  {
   $nextPage = "<a href=\"".$this->pageStr.($this->page+1)."\">下一页</a>";
  }
  //如果没到尾页则显示尾页连接
  if($this->page<$this->pageCount)
  {
   $lastPage = "<a href=\"".$this->pageStr.$this->pageCount."\">尾页</a>";
  }
  //所有页码列表
  for($counter=1;$counter<=$this->pageCount;$counter++)
  {
   if($this->page == $counter)
   {
    $currentPage = "<b>".$counter."</b>";
   }
   else
   {
    $currentPage = " "."<a href=\"".$this->pageStr.$counter."\">".$counter."</a>"." ";
   }
   $pageList .= $currentPage;
  }
  return $firstPage." ".$previousPage." ".$pageList." ".$nextPage." ".$lastPage." ";
 }
}
?>

<?php
@$db = mysql_connect('localhost', 'root', '123456') or
  die("Could not connect to database.");//连接数据库
mysql_query("set names 'utf8'");//输出中文
mysql_select_db('test');  //选择数据库
$sql = "select * from `users`"; //一个简单的查询
$page = new Page('',$sql,$_GET['page'],5,"?page=");
$rows = $page->list;
foreach($rows as $row)
{
 echo $row['UserName']."<br>";
}
echo $page->getPageList(); //输出分页列表
?>