PHP+MYSQL实例：网站在线人数的程序代码

网络整理 - 08-17

以下为引用的内容：
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PHP实例教程：网站在线人数的程序代码，后台有MYSQL数据库支持。可以直接统计出网站当前的在线人数。
首先是创建MYSQL数据库表。
CREATE TABLE tablename ( field type(max_length) DEFAULT 'default_value' (NOT) NULL }
可以使用的SQL语句。
CREATE TABLE useronline ( timestamp int(15) DEFAULT '0' NOT NULL, ip varchar(40) NOT NULL, file varchar(100) NOT NULL, PRIMARY KEY (timestamp), KEY ip (ip), KEY file (file) );
下面我们开始使用PHP脚本，首先定义MYSQL的信息。
server = "localhost"; //你的服务器 db_user = "root"; //你的mysql的用户名 db_pass = "password"; //你的mysql的密码 database = "users"; //表的名字
设置统计的时间(多少秒内在线人数)
timeoutseconds = 300;
取当前时间。
timestamp = time();
上面的完整代码：
<?php server = "localhost"; //your server db_user = "root"; //your mysql database username db_pass = "password"; //your mysql database password if any database = "users"; //the db name timeoutseconds = 300;//timeoutseconds limit //get the current time timestamp = time(); //calculate the lowest timestamp allowed timeout = timestamp-timeoutseconds; ?>
连接mysql
mysql_connect('localhost', 'username', 'password');
也允许使用变量形式。
mysql_connect(server, db_user, db_pass);
如果mysql数据库没有密码的话可以使用下面代码连接（当然建议大家一定要设置好自己的密码，这样起码黑客得要解密啊）
mysql_connect(server, db_user);
查询数据库的代码：
mysql_db_query('database', 'query');
我们只要有访客就要增加一条记录。
insert = mysql_db_query(database, "INSERT INTO useronline VALUES ('timestamp','"._SERVER['REMOTE_ADDR']."','"._SERVER['PHP_SELF']."')");
然后我们给出如果用户用错误信息的处理方式。
if(!(insert)) { print "Useronline Insert Failed > "; }
然后我们得实现当超过我们设置的时间我们就要删除该用户记录。
delete = mysql_db_query(database, "DELETE FROM useronline WHERE timestamp<timeout");
同样给出删除记录出错的处理。
if(!(delete)) { print "Useronline Delete Failed > "; }
下面我们显示数据库中有多少个不同的IP
result = mysql_db_query(database, "SELECT DISTINCT ip FROM useronline WHERE file='"._SERVER['PHP_SELF']."' ");
我们使用
mysql_num_rows(query);
来统计用户，代码如下。
user = mysql_num_rows(result);
最后我们要关闭数据库。
mysql_close();
显示在线的人数。
if(user == 1) { print("1 user online\n"); } else { print("user users online\n"); }
最终把上面代码写成一个PHP文件如下。
<?php //Put your basic server info here server = "localhost"; //normally localhost db_user = "root"; //your MySQL database username db_pass = "password"; //your MySQL database password database = "users"; timeoutseconds = 300; //it will delete all people which haven't refreshed(so probbably are // offline or inactive) in timieoutseconds time (so it actually checks the people that are active in the last // timeoutseconds seconds) //this is where PHP gets the time timestamp = time(); //counts the timeout, all people which have been seen last online in earlier than this timestamp, will get removed timeout = timestamp-timeoutseconds; //connect to database mysql_connect(server, db_user); //add the timestamp from the user to the online list insert = mysql_db_query(database, "INSERT INTO useronline VALUES ('timestamp','"._SERVER['REMOTE_ADDR']."','"._SERVER['PHP_SELF']."')"); if(!(insert)) { print "Useronline Insert Failed > "; } //delete the peoples which haven't been online/active in the last timeoutseconds seconds. delete = mysql_db_query(database, "DELETE FROM useronline WHERE timestamp<timeout"); if(!(delete)) { print "Useronline Delete Failed > "; } //select the amount of people online, all uniques, which are online on THIS page result = mysql_db_query(database, "SELECT DISTINCT ip FROM useronline WHERE file='"._SERVER['PHP_SELF']."' "); if(!(result)) { print "Useronline select Error > "; } //Count the number of rows = the number of people online user = mysql_num_rows(result); //spit out the results mysql_close(); if(user == 1) { print("1 user online\n"); } else { print("user users online\n"); } ?></DIV>