PHP通用分页

代码如下：

 0 ? intval($page) : 1;$conn = mysql_connect("127.0.0.1","root","") or die('连接数据库失败');mysql_select_db("demo",$conn);mysql_query("SET NAMES UTF8");$pageSize = 10;//每页显示的数据$showPage = 5;//显示页码$sql = "select * from demo limit ".($page-1)*$pageSize.",".$pageSize;$result = mysql_query($sql,$conn);echo '';echo '';while($row = mysql_fetch_assoc($result)){    echo '';    echo '';    echo '';    echo '';}echo '
ID
NAME
'.$row['id'].'
'.$row['name'].'
';mysql_free_result($result);$total_sql = "select count(*) from demo";$total_result = mysql_fetch_array(mysql_query($total_sql));$total = $total_result[0];//计算总页数$total_page = ceil($total/$pageSize);mysql_close($conn);/*分页条*/$page_banner = '';//偏移量$pageOffset = ($showPage-1)/2;if ($page > 1) {    $page_banner .= '首页 ';    $page_banner .= '<<上一页 ';} else {    $page_banner .= '首页';    $page_banner .= '<<上一页';}//page start//初始化数据$start = 1;$end = $total_page;if ($total_page > $showPage){    if ($page > $pageOffset+1) {        $page_banner.= '...';    }    if ($page > $pageOffset) {        //开始位置总是当前页-偏移量        $start = $page - $pageOffset;        //右边的显示码加偏移量小于总页数就显示当前页+偏移量否则就显示最后页        $end = $total_page > ($page + $pageOffset) ? ($page + $pageOffset) : $total_page;    } else {        $start = 1;        $end = $total_page > $showPage ? $showPage : $total_page;    }    if ($page+$pageOffset > $total_page) {        //实际的开始位置-(当前位置+偏移量-最后一页)        $start = $start - ($page + $pageOffset - $end);    }}for($i = $start; $i <= $end; $i++ ){    if ($page == $i) {        $page_banner .= ''.$i.'';    } else {        $page_banner .= ''.$i.'';    }}if ($total_page > $showPage && $total_page > $page + $pageOffset) {    $page_banner.= '...';}//page endif ($page < $total_page) {    $page_banner .= '下一页>>';    $page_banner .= '尾页';} else {    $page_banner .= '下一页>>';    $page_banner .= '尾页';}$page_banner .= '共'.$total_page.'页';$page_banner .= '到第';echo $page_banner;