作业4-2（带用户的留言板）单页面实现！ | 斯人笔记本 - IMSRY

演示页面：http://www.dshui.wang/html/board2.php
本次作业基于作业4-1完成，部分文件在4-1中给出：
所需要的数据表：

CREATE TABLE `msg` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `content` varchar(254) NOT NULL DEFAULT '',
  `username` char(10) DEFAULT '',
  `stime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

CREATE TABLE `user` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `username` char(20) NOT NULL DEFAULT '',
  `pwd` varchar(20) NOT NULL DEFAULT '',
  `registtime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

文件board2.php

<?php
include './mysqlconfig.php';
session_start();
if($_POST['do']=="login"){
	$username = $_POST['username'];
	$pwd = $_POST['passwd'];
	$sql = "select * from user where username='$username' and pwd='$pwd';";
	$res = mysql_query($sql);
	$row = mysql_fetch_assoc($res);
	if ($row['id'] <> ''){
		$_SESSION['username'] = $row['username'];
		echo "<script>alert('登陆成功！')</script>";
	}else{
		echo "<script>alert('登录失败！用户名或密码错误！')</script>";
	}
	header ( "refresh:0;url=" );
}elseif($_POST['do']=="registe"){
	$rname = $_POST['rname'];
	$rpwd = $_POST['rpasswd'];
	$sql = "insert into user(username,pwd) values ('$rname','$rpwd');";
	if(mysql_query($sql)){
		$_SESSION['username'] = $rname;
		echo "<script>alert('注册成功！已经为您自动登录！')</script>";
	}else{
		echo "<script>alert('注册失败！')</script>";
	}
	header ( "refresh:0;url=" );
}elseif($_POST['do']=="submit"){
	$content = $_POST['content'];
	echo $content;
	$sql = "insert into msg(content,username) values (\"{$content}\",'".$_SESSION['username']."');";
	if(mysql_query($sql)){
		echo "<script>alert('留言成功！')</script>";
		header ( "refresh:0;url=" );
	}else{
		echo "<script>alert('不知道怎么的，留言失败了。')</script>";
	}
}elseif($_POST['do']=="logout"){
	session_unset();
	session_destroy();
	echo "<script>alert('成功退出登陆！')</script>";
	header ( "refresh:0;url=" );
}
$sql = "select * from msg order by id desc;";
$result = mysql_query($sql);
?>
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>简易留言板(带用户验证)</title>
<style type="text/css">
#tab {
BORDER-BOTTOM: #c2130e 3px solid; HEIGHT: 60px
}
#tab p{
FLOAT: left; LINE-HEIGHT: 21px; text-align:center
}
#tab p.hit {
BACKGROUND: #dcdcdc; BORDER-LEFT: #f2f2f2 1px solid; WIDTH: 40px; CURSOR: pointer
}
#tab p.nhit {
BACKGROUND: #c2130e; BORDER-LEFT: #f2f2f2 1px solid; WIDTH: 40px; COLOR: #fff
}
</style>
</head>

<body bgcolor="#56FF00">
	<div style="margin:0 auto;width:400px;">
	<?php if(!isset($_SESSION['username']) || $_SESSION['username']==''){?>
		<div id="usertip" class="login">

注意：只有登陆之后才能进行留言哦！

			<div id="tab">

登陆

注册

			</div>
			<div id="login">
				<form name="login" method="post">
					<input type="hidden" name="do" value="login">
					<table>
						<tr>
							<td>用户名：</td>
							<td><input type="text" name="username" ></td>
						</tr>
						<tr>
							<td>密&nbsp;&nbsp;&nbsp;&nbsp;码：</td>
							<td><input type="password" name="passwd" ></td>
						</tr>
						<tr>
							<td></td>
							<td align="right"><input type="submit" value="登陆" /></td>
						</tr>
					</table>
				</form>
			</div>
			<div id="reg" style="display: none;">
				<form name="registe" method="post">
					<input type="hidden" name="do" value="registe">
					<table>
						<tr>
							<td>用户名：</td>
							<td><input type="text" name="rname" ></td>
						</tr>
						<tr>
							<td>密&nbsp;&nbsp;&nbsp;&nbsp;码：</td>
							<td><input type="password" name="rpasswd" ></td>
						</tr>
						<tr>
							<td></td>
							<td align="right"><input type="submit" value="注册" /></td>
						</tr>
					</table>
				</form>
			</div>
		</div>
	<?php }else{?>
        <div class="form">

        		当前用户：<?php echo $_SESSION['username'];?>
        		<form method="post">
        		<input type="hidden" name="do" value="logout">
        		<input type="submit"value="退出登录">
        		</form>

            <form method="post">
            <textarea name="content" cols="45" rows="5" style="width: 400px; height: 88px;"></textarea>

			<input type="hidden" name="do" value="submit">
            <div align="right"><input type="submit" value="留言" />&nbsp;</div>
            </form>
        </div>
    <?php }?>
        <div class="msg">
        	<table border="1" bordercolor="#FFFFFF">
        	<?php while ($rows = mysql_fetch_assoc($result)){?>
            	<tr>
                	<td><span><?php echo $rows['username'];?> </span><span class="datetime">（<?php echo $rows['stime'];?>）</span>
<span class="content"><?php echo $rows['content'];?></span></td>
                </tr>
            <?php }?>
            </table>
        </div>
	</div>
<script>
var Tags=document.getElementById('tab').getElementsByTagName('p'); 
var usertip=document.getElementById('usertip').getElementsByTagName('div');
var len=Tags.length; 
var flag=0;//修改默认值
for(i=0;i<len;i++){
Tags[i].value = i;
Tags[i].onmouseover=function(){changeNav(this.value)}; 
}
Tags[flag].className='nhit';
function changeNav(v){ 
	Tags[flag].className='hit';
	usertip[flag+1].style.display="none";
	flag=v; 
	Tags[v].className='nhit';
	usertip[v+1].style.display="";
}
</script>
</body>
</html>