php网站怎么写一个聊天
网页聊天室我们可以使用多种方式实现，比如websocket，或是使用第三方的聊天服务，下面介绍一种最简单的方式，不断刷新页面获取信息。
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1、数据库建立
create table chat ( chattime datetime, nick char(10), words char(150) );
login.php
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<html> <head> <title>用户登录</title> <meta charset="utf-8"> </head> <body>请输入您的昵称<br> <form action="main.php" method="post" target="_self"> //点击登录后跳转到main.php，并将输入的数据用post的方式发送过去 <input type="text" name="nick" cols="20"> <input type="submit" value="登录"> </body> </html>
main.php
<?php session_start(); $_SESSION['nick'] = $_POST['nick']; //获取login.php发送过来的数据，也就是用户昵称，并将它保存在session中用于对用户进行跟踪 ?> <html> <frameset rows="80%, 20%"> <frame src="cdisplay.php" name="chatdisplay"/> // 聊天信息展示区 <frame src="speak.php" name="speak"/> //发言区 </frameset> </html>
speak.php
<html>
<head>
<title>发言</title>
<meta charset="utf-8">
</head>
<body>
<?php
session_start(); //如果设置北京时间，需要加上 date_default_timezone_set('PRC');
if ($_POST['words']) {
$conn = mysql_connect("127.0.0.1","root","******"); //连接数据库
mysql_select_db("yuema", $conn);
$time = date(y).date(m).date(d).date(h).date(i).date(s); //当前时间
$nick = $_SESSION['nick'];
$words = $_POST['words'];
$str = "insert into chat(chattime, nick, words) values('$time', '$nick', '$words');";
mysql_query($str, $conn); //将用户名，时间和发言内容进行插入
mysql_close($conn);
}
?>
<form action="speak.php" method="post" target="_self">
<input type="text" name="words" cols="20">
<input type="submit" value="发言">
</form>
</body>
</html>cdisplay.php
<html>
<head>
<title>显示用户发言</title>
<meta http-equiv="refresh" content="5;url=cdisplay.php"> //设置每隔5秒钟刷新一次
</head>
<body>
<?php
$conn = mysql_connect("127.0.0.1", "root", "******");
mysql_select_db("yuema", $conn);
$str = "select * from chat order by chattime;";
$result = mysql_query($str, $conn);
$rows = mysql_num_rows($result);
mysql_data_seek($result, $rows-15); //取最近插入的15条数据
if ($rows<15)
$l = $rows;
else
$l = 15;
for ($i = 1; $i <= $l; $i++) { //输出这15条数据
list($chattime, $nick, $words) = mysql_fetch_row($result);
echo $chattime;
echo " ".$nick." ";
echo $words;
echo "<br>";
}
?>
</body>
</html>结果展示
2. ajax获取，不刷新页面
login.php
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<html> <head> <title>用户登录</title> <meta charset="utf-8"> </head> <body>请输入您的昵称<br> <form action="main.php" method="post" target="_self"> //点击登录后跳转到main.php，并将输入的数据用post的方式发送过去 <input type="text" name="nick" cols="20"> <input type="submit" value="登录"> </body> </html>
main.php
<?php session_start(); $_SESSION['nick'] = $_POST['nick']; //获取login.php发送过来的数据，也就是用户昵称，并将它保存在session中用于对用户进行跟踪 ?> <html> <frameset rows="80%, 20%"> <frame src="cdisplay.php" name="chatdisplay"/> // 聊天信息展示区 <frame src="speak.php" name="speak"/> //发言区 </frameset> </html>
speak.php
<html>
<head>
<title>发言</title>
<meta charset="utf-8">
</head>
<body>
<?php
session_start(); //如果设置北京时间，需要加上 date_default_timezone_set('PRC');
if ($_POST['words']) {
$conn = mysql_connect("127.0.0.1","root","******"); //连接数据库
mysql_select_db("yuema", $conn);
$time = date(y).date(m).date(d).date(h).date(i).date(s); //当前时间
$nick = $_SESSION['nick'];
$words = $_POST['words'];
$str = "insert into chat(chattime, nick, words) values('$time', '$nick', '$words');";
mysql_query($str, $conn); //将用户名，时间和发言内容进行插入
mysql_close($conn);
}
?>
<form action="speak.php" method="post" target="_self">
<input type="text" name="words" cols="20">
<input type="submit" value="发言">
</form>
</body>
</html>cdisplay.php
<html>
<head>
<meta charset="utf-8">
<title>显示用户发言</title>
<script type="text/javascript" src="jquery.js"></script> //jquery库，jquery.js可以在网上下载
<script type="text/javascript">
setInterval('show()', 3000); // 设置自动刷新时间 3000毫秒也就是3秒钟
function show() {
$.ajax({
url:'server_get.php', //请求发送到server_get.php进行处理
type:'post',
dataType:'html',
error:function() {
alert('请求失败，请稍后再试');
},
success:function(msg) {
$('p').html(msg); //设置body中p标签的内容
}
});
}
</script>
</head>
<body>
<p></p>
</body>
</html>server_get.php
<?php
$conn = mysql_connect("127.0.0.1", "root", "******");
mysql_select_db("yuema", $conn);
$str = "select * from chat order by chattime;";
$result = mysql_query($str, $conn);
$rows = mysql_num_rows($result);
mysql_data_seek($result, $rows-15);
if ($rows < 15)
$l = $rows;
else
$l = 15;
$string = "";
for ($i = 1; $i <= $l; $i++) {
list($chattime, $nick, $words) = mysql_fetch_row($result);
$string.=$chattime;
$string.=" ";
$string.=$nick;
$string.=" ";
$string.=$words;
$string.="<br>";
}
echo $string;
?> 
