从一个不错的留言本弄的mysql数据库操作类，初学php的朋友可以参考下
<?php
class mysql{
var $querynum = 0;
function connect($dbhost, $dbuser, $dbpw, $dbname = '',$dbcharset='') {
if(!@mysql_connect($dbhost, $dbuser, $dbpw)) {
$this->show('Can not connect to MySQL server');
return false;
}
if($dbname) {
$this->select_db($dbname);
}
if($this->version() > '4.1' && $dbcharset) {
$this->query("SET NAMES '".$dbcharset."'");
}
return true;
}
function select_db($dbname) {
return mysql_select_db($dbname);
}
function fetch_array($query, $result_type = MYSQL_ASSOC) {
return @mysql_fetch_array($query, $result_type);
}
function query($sql, $type = '') {
if(!($query = mysql_query($sql))) $this->show('MySQL Query Error', $sql);
$this->querynum++;
return $query;
}
function affected_rows() {
return mysql_affected_rows();
}
function result($query, $row) {
return mysql_result($query, $row);
}
function num_rows($query) {
return @mysql_num_rows($query);
}
function num_fields($query) {
return mysql_num_fields($query);
}
function free_result($query) {
return mysql_free_result($query);
}
function insert_id() {
return mysql_insert_id();
}
function fetch_row($query) {
return mysql_fetch_row($query);
}
function version() {
return mysql_get_server_info();
}
function close() {
return mysql_close();
}
function error() {
return mysql_error();
}
function show($message = '', $sql = '') {
if(!$sql) echo $message;
else echo $message.'<br>'.$sql.'<br>'.$this->error();
}
}
class page extends mysql{
function pagination($sql,$maxnum,$page,$maxpages,$pagepre,$ext=''){
global $sum,$stail,$link,$lmid,$ltail,$curpage;//$ext='&class=3'
$SELF = $_SERVER['PHP_SELF'];
$query = $this->query($sql);
$rows = $this->fetch_array($query,MYSQL_NUM);
$totalrows = $rows[0];
$totalpages = ceil($totalrows/$maxnum);
$startnum = ($page - 1)*$maxnum;
$string = $sum.$totalrows.$stail.$sum.$page."/".$totalpages.$stail;
if($page != 1){
$string .= $link.$SELF."?page=1".$ext.$lmid."|‹".$ltail;
$string .= $link.$SELF.'?page='.($page - 1).$ext.$lmid."‹‹".$ltail;
}
if($maxpages>=$totalpages){
$pgstart = 1;$pgend = $totalpages;
}
elseif(($page-$pagepre-1+$maxpages)>$totalpages){
$pgstart = $totalpages - $maxpages + 1;
$pgend = $totalpages;
}
else{
$pgstart=(($page<=$pagepre)?1:($page-$pagepre));
$pgend=(($pgstart==1)?$maxpages:($pgstart+$maxpages-1));
}
for($pg=$pgstart;$pg<=$pgend;$pg++){
if($pg == $page){
$string .= $curpage.$SELF."?page=".$pg.$ext.$lmid.$pg.$ltail;
}
else $string .= $link.$SELF."?page=".$pg.$ext.$lmid.$pg.$ltail;
}
if($page != $totalpages){
$string .= $link.$SELF.'?page='.($page + 1).$ext.$lmid."››".$ltail;
$string .= $link.$SELF.'?page='.$totalpages.$ext.$lmid."›|".$ltail;
}
return $string;
}
}
function html($str,$allowhtml=0){
$str = get_magic_quotes_gpc()?$str:addslashes($str);
if(!$allowhtml){$str = htmlspecialchars($str);}
return $str;
}
function dehtml($str,$allowhtml=0){
$str = stripslashes($str);
if(!$allowhtml){$str = nl2br($str);}
return $str;
}
function deip($str){
$arr = explode('.',$str);
$str = $arr[0].'.'.$arr[1].'.'.$arr[2].'.*';
return $str;
}
function setting($login=false){
global $db,$mydbpre;
if($login) $sql = "select * from {$mydbpre}setting";
else $sql = "select * from {$mydbpre}setting where keyword != 'username' and keyword != 'password'";
$query = $db->query($sql);
while($row = $db->fetch_array($query)){
$arr[$row['keyword']] = $row['val'];
if($row['keyword'] == 'name') $arr['title'] = $row['val'].' - Powered by PHPfans';
}
return $arr;
}
function checkcontent($content){
global $db,$mydbpre,$mearr;
$arrword = $arrip = array();
$sql = "select * from {$mydbpre}ban where b_type != 0";
$query = $db->query($sql);
while($row = $db->fetch_array($query)){
if($row['b_type'] == 1) $arrword[] = $row['b_val'];
elseif($row['b_type'] == 2) $arrip[] = $row['b_reval'];
}
foreach($arrip as $value){
$value = preg_quote($value,'/');
$value = str_replace('\*','\d{1,3}',$value);
if(preg_match('/^('.$value.')$/',$_SERVER['REMOTE_ADDR'])){
showmessage($mearr[8],'index.php');
}
}
foreach($arrword as $val){
$val = preg_quote($val,'/');
if(preg_match('/'.$val.'/',$content)){
showmessage($mearr[7],'index.php');
}
}
}
function replaceword($content){
global $db,$mydbpre;
$sql = "select * from {$mydbpre}ban where b_type = 0";
$query = $db->query($sql);
while($row = $db->fetch_array($query)){
$content = str_replace($row['b_val'],$row['b_reval'],$content);
}
return $content;
}
function showadmin($message,$referer=''){
$str = '';
if($referer != '') $str .= '<meta http-equiv="refresh" content="2;URL='.$referer.'" />';
$str .= '
<table width="45%" align="center" style="border:1px solid #eeeeee; margin-top:50px;">
<tr bgcolor="#CCCCCC">
<td height="25">信息提示</td>
</tr>
<tr align="center">
<td style="padding:10px 0 10px 0">'.$message;
if($referer != '') $str .= '<br />
<br />
<a href="'.$referer.'">如果你的页面没有跳转,请点这里</a>';
$str .= '
</td>
</tr>
</table>';
echo $str;
exit;
}
function showmessage($message,$referer=''){
global $setting,$db;
$start = gettime();
echo <<<EOT
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk" />
<title>php爱好者留言簿_提示信息</title>
<link type="text/css" href="guest.css" rel="stylesheet">
EOT;
if($referer != '') echo '<meta http-equiv="Refresh" content="2;URL='.$referer.'" />';
echo <<<EOT
</head>
<body>
<center>
EOT;
require_once('header.html');
echo <<<EOT
<div class="message">
<h1>php爱好者留言簿 提示信息</h1>
{$message}
EOT;
if($referer != ''){
echo <<<EOT
<br />
<a href="{$referer}">如果您的浏览器没有自动跳转，请点击这里</a>
</div>
EOT;
}
require_once('footer.html');
echo <<<EOT
</center>
</body>
</html>
EOT;
exit;
}
function gettime()
{
$t = explode(" ",microtime());
return $t[1] + $t[0];
}
function checklogin($exit=true){
if(!isset($_COOKIE['islogin']) || $_COOKIE['islogin'] != 1){
if($exit) {
echo "请先登陆，谢谢。";
exit;
}
}
else setcookie('islogin',1,time()+60*20);
}
?>