Question

我一直在尝试在我的网站上找到会话ID，所以我可以用它来查询我的MySQL数据库，但我一直收到错误'未定义变量：_SESSION in ...'

这是我的代码：

if (mysql_num_rows(mysql_query("SELECT * FROM users WHERE _id = " . $_SESSION['_id_of_user'])))

这是我定义会话ID的地方：

$qry = "Select name, email, username, _id from $this->tablename where username='$username' and password='$pwdmd5' and confirmcode='y'";

$result = mysql_query($qry,$this->connection);

if(!$result || mysql_num_rows($result) <= 0)
{
    $this->HandleError("Error logging in. The username or password does not match");
    return false;
}

$row = mysql_fetch_assoc($result);

$_SESSION['name_of_user']     = $row['name'];
$_SESSION['email_of_user']    = $row['email'];
$_SESSION['username_of_user'] = $row['username'];
$_SESSION['_id_of_user']      = $row['_id'];

Answer 1

您必须在SQL查询之前启动会话： http://us.php.net/manual/en/function.session-start.php

session_start();

然后你应该得到当前的会话ID： http://us.php.net/manual/en/function.session-id.php

$current_session_id = session_id();

Answer 2

在尝试写入之前你做了session_start()吗？还试着把

var_dump("<PRE>", $_SESSION);

在你尝试阅读之前，看看其中是什么。所以你会：

session_start();
$_SESSION['name_of_user']     = $row['name'];
$_SESSION['email_of_user']    = $row['email'];
$_SESSION['username_of_user'] = $row['username'];
$_SESSION['_id_of_user']      = $row['_id'];

和

var_dump("<PRE>", $_SESSION);
$qry = "Select name, email, username, _id from $this->tablename where username='$username' and password='$pwdmd5' and confirmcode='y'";

另外，我想知道你是否可以用$ this-＆gt; tablename：

来做到这一点

$qry = "Select name, email, username, _id from $this->tablename where username='$username' and password='$pwdmd5' and confirmcode='y'";

尝试：

 $qry = "Select name, email, username, _id from ".$this->tablename." where username='$username' and password='$pwdmd5' and confirmcode='y'";

PHP在数据库中查询Session_ID

2 个答案: