Question

我曾经用旧的方式在php中编码，并通过这个论坛介绍给POO。我正在将mysql中的脚本重写为PDO。此脚本用于显示网站上已连接成员的编号和名称。到目前为止，它只显示数字，但尚未显示已连接成员的名称列表

脚本已更新：

<?php

session_start();

if(isset($_SESSION['nom'])){ 
   include('class.connect.php');
   include('class.user.php');

    $db = new DBEngine();

   //verify if the name is already in the table
    $log = $db->con->prepare('SELECT COUNT(nom) AS name FROM members_connected WHERE nom=?');
    $log->execute(array($_SESSION['nom']));


    $count = $log->fetchColumn(0);
     $time = time();
    if ($count == 0) 
    {

        // the user is not in the new table, i add him
       $log = $db->con->prepare('INSERT INTO members_connected (nom,timestamp) VALUES(?,?)');
       $log->execute(array($_SESSION['nom'],$time));
    }

    //name already in the table, update the timestamp
    else 
    {

        $log = $db->con->prepare('UPDATE members_connected SET timestamp=? WHERE nom=?');

        $log->execute(array($_SESSION['name'],$time));
    }

    //5 min earlier's timestamp
    $timestamp_5min = time() - (60 * 5); 

    $log = $db->con->prepare('DELETE FROM members_connected WHERE timestamp < ?');
    $log->  execute(array($timestamp_5min));

    $log = $db->con->prepare('SELECT nom FROM members_connected');
    $log->execute();
    $row = $log->fetch(PDO::FETCH_ASSOC);

    echo  $count ;

    //show the list of connected              
    if($count > 0)
    {
        $i=0;
        while($count = $log->fetch(PDO::FETCH_ASSOC));
        {
            $i++;
            echo $count['nom'];
            if($i<$row)
            {
                //space between names
                echo ',';
            }
        }
    }
}

＆GT;

有什么想法吗？

Answer 1

尝试在第二次加入后添加以下内容;

$db = new DBEngine();

然后在您拥有的代码中

$this->db->con->prepare(...

将其更改为

$db->con->prepare(...

<强>更新在回答第二个错误时，您似乎需要在绑定中设置变量类型。

e.g。

$log->bindParam(1, $_SESSION['name'], PDO::PARAM_STR, 25);
$log->bindParam(2, time(), PDO::PARAM_STR, 20);

或者，您不需要像这样绑定变量，您可以将它们直接传递到execute，就像这样（这是您在第一个查询中所拥有的）btw

$log->execute(array($_SESSION['name'], time()));

Answer 2

创建一个TimeStamp类，用于获取和更新数据库，如下所示：

class TimeStamp
    {
        protected   $db;

        public  $row_count;
        public  function __construct($db)
            {
                $this->db   =   $db;
            }

        // This should grab all users connected
        public  function Fetch($_user, $interval = '1')
            {
                // This is just checking a time range and collecting names
                // You may want to make a new function that will then take the return list and query your user info table to get the user info
                $connected  =   $this->db->con->prepare("select * FROM members_connected WHERE timestamp > DATE_SUB(NOW(), INTERVAL $interval MINUTE)");
                $connected->execute(array($_user));

                if($connected->rowCount() > 0) {
                        while($result = $connected->fetch(PDO::FETCH_ASSOC)) {
                                $users[]    =   $result;
                            }

                    }

                // This should get the count
                $this->row_count    =   (isset($users))? count($users):0;

                // Return if users are available
                return (isset($users))? $users:0;
            }

        public  function Record($_user)
            {
                $connected  =   $this->db->con->prepare("INSERT INTO members_connected (nom, timestamp) VALUES (:nom,NOW()) ON DUPLICATE KEY UPDATE timestamp = NOW()");
                $connected->bindParam(':nom', $_user);
                $connected->execute();
            }
    }


include('class.connect.php');
include('class.user.php');

$db     =   new DBEngine();

if(isset($_SESSION['nom'])) {
        // Start the timestamp, feed database
        $u_check    =   new TimeStamp($db);

        // Record into db
        $u_check->Record($_SESSION['nom']);

        // Check db, print users
        $users  =   $u_check->Fetch($_SESSION['nom']);
        print_r($users);

        // Display count
        echo "USERS: ".$u_check->row_count;
    }

显示已连接用户的号码和名称

2 个答案: