PHP+MYSQL實例：網站在線人數的程序代碼

PHP實例教程：網站在線人數的程序代碼，後台有MYSQL數據庫支持。可以直接統計出網站當前的在線人數。

首先是創建MYSQL數據庫表。

CREATE TABLE tablename (
field type(max_length) DEFAULT default_value (NOT) NULL
}

可以使用的SQL語句。

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)
);

下面我們開始使用PHP腳本，首先定義MYSQL的信息。

$server = "localhost"; //你的服務器
$db_user = "root"; //你的mysql的用戶名
$db_pass = "password"; //你的mysql的密碼
$database = "users"; //表的名字

設置統計的時間(多少秒內在線人數)

$timeoutseconds = 300;

取當前時間。

$timestamp = time();

上面的完整代碼：

<?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;
?>

連接mysql

mysql_connect(localhost, username, password);

也允許使用變量形式。

mysql_connect($server, $db_user, $db_pass);

如果mysql數據庫沒有密碼的話可以使用下面代碼連接（當然建議大家一定要設置好自己的密碼，這樣起碼黑客得要解密啊）

mysql_connect($server, $db_user);

查詢數據庫的代碼：

mysql_db_query(database, query);

我們只要有訪客就要增加一條記錄。

$insert = mysql_db_query($database, "INSERT INTO useronline VALUES
($timestamp,".$_SERVER[REMOTE_ADDR].",".$_SERVER[PHP_SELF].")");

然後我們給出如果用戶用錯誤信息的處理方式。

if(!($insert)) {
print "Useronline Insert Failed > ";
}

然後我們得實現當超過我們設置的時間我們就要刪除該用戶記錄。

$delete = mysql_db_query($database, "DELETE FROM useronline WHERE timestamp<$timeout");

同樣給出刪除記錄出錯的處理。

if(!($delete)) {
print "Useronline Delete Failed > ";
}

下面我們顯示數據庫中有多少個不同的IP

$result = mysql_db_query($database, "SELECT DISTINCT ip FROM useronline WHERE file=".$_SERVER[PHP_SELF]." ");

我們使用

mysql_num_rows(query);

來統計用戶，代碼如下。

$user = mysql_num_rows($result);

最後我們要關閉數據庫。

mysql_close();

顯示在線的人數。

if($user == 1) {
print("1 user online ");
} else {
print("$user users online ");
}

最終把上面代碼寫成一個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 havent 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 havent 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);