PHP+mysql+ajax轻量级聊天室实例(兼容Chrome和IE)

做了一个QQ聊天交友网站，想加个聊天的功能，于是做完用PHP做了简单又强大的聊天室

1. 创建mysql数据库表：create table chat( id bigint AUTO_INCREMENT,username varchar(20), chatdate datetime,msg varchar(500), primary key(id));

2.编写建议连接数据库函数：

dbconnect.php

function db_connect()
{

  date_default_timezone_set("Asia/Shanghai");

  $link = mysql_connect("xxx.xxx.xxx.xxx", "databasename", "password")
            or die('无法连接: ' . mysql_error());
  mysql_select_db("databasename") or die('没有你找到指定数据库');
  return true;
}

function quote($strText)
{
    $Mstr = addslashes($strText);
    return "'" . $Mstr . "'";
}

function isdate($d)
{
   $ret = true;
   try
   {
       $x = date("d",$d);
   }
   catch (Exception $e)
   {
       $ret = false;
   }
   echo $x;
   return $ret;
}

 
?>
3. 编写ajax发送和接收函数：

ajax发送函数chat_send_ajax.php

     require_once('dbconnect.php');

     db_connect();

     $msg = iconv("UTF-8","GB2312",$_GET["msg"]);
     $dt = date("Y-m-d H:i:s");
     $user = iconv("UTF-8","GB2312",$_GET["name"]);

     $sql="INSERT INTO chat(USERNAME,CHATDATE,MSG) " .
          "values(" . quote($user) . "," . quote($dt) . "," . quote($msg) . ");";

          echo $sql;

     $result = mysql_query($sql);
     if(!$result)
     {
        throw new Exception('Query failed: ' . mysql_error());
        exit();
     }

?>

ajax接收函数chat_recv_ajax.php

header("Content-Type:text/html;charset=gb2312");
header("Expires: Thu, 01 Jan 1970 00:00:01 GMT");
   header("Cache-Control: no-cache, must-revalidate");
   header("Pragma: no-cache");
     require_once('dbconnect.php');

     db_connect();
    
     $sql = "SELECT *, date_format(chatdate,'%Y年%m月%d日 %r') as cdt from chat order by ID desc limit 200";
     $sql = "SELECT * FROM (" . $sql . ") as ch order by ID";
     $result = mysql_query($sql) or die('Query failed: ' . mysql_error());
    
     // Update Row Information
     $msg="

?>

4.聊天室页面：

chat.html