php - PDO 在函数外工作，在函数内不起作用

Question

我正在尝试验证 PDO 中的登录，但它在函数内部时不起作用。我也尝试将 $db 添加到函数中，但没有帮助。无论发生什么，它都会回显“坏”，如果我将它从函数中删除，它可以使用完全相同的代码正常工作。这是全部内容:

function logIn($db)
{
    try
    {
        $stmt = $db->prepare("SELECT COUNT(*) FROM users WHERE Username = :user AND Usernameclean = :userclean AND Password = :pass");
        $stmt->bindParam(":user", $user);
        $stmt->bindParam(":userclean", $userclean);
        $stmt->bindParam(":pass", $pass);
        $stmt->execute();
        $status = (bool) $stmt->fetchColumn(0);
        if ($status)
        {
            echo "good";
        }
        else
        {
            echo "bad";
        }
    }
    catch (PDOException $e)
    {
    echo "There was a problem connecting to this database.";
    $e->getMessage();
    }
}
logIn($db);

Answer 1

您还必须将在函数内部使用的其他变量传递给该函数。

因此，正确的函数应该是:

function logIn($db, $user, $userclean, $pass)
{
    try
    {
        $stmt = $db->prepare("SELECT COUNT(*) FROM users WHERE Username = :user AND Usernameclean = :userclean AND Password = :pass");
        $stmt->bindParam(":user", $user);
        $stmt->bindParam(":userclean", $userclean);
        $stmt->bindParam(":pass", $pass);
        $stmt->execute();
        $status = (bool) $stmt->fetchColumn(0);
        if ($status)
        {
            echo "good";
        }
        else
        {
            echo "bad";
        }
    }
    catch (PDOException $e)
    {
    echo "There was a problem connecting to this database.";
    $e->getMessage();
    }
}
logIn($db, $user, $userclean, $pass);