$ wpdb-> get_var工作不适合我($wpdb->get_var isn't

我工作的一个PayPal IPN处理程序，得到的IPN然后发送电子邮件。现在我正在测试它试图访问我的数据库的“付费”列，以确保交易尚未以前被处理。然而WPDB $似乎不正确返回的东西。我能够使用WPDB $另一种形式的插入东西到数据库中，但我无法得到它回来了。我试图get_var，get_row，和get_results并试图访问它们作为对象，阵列或在get_var的情况下的变量。

$paidstatus = $wpdb->get_var("SELECT paid FROM wp_bbbiller WHERE txn_id = '$txn_id'");

$subject = 'Test e-mail';
$message = "Thank you for your purchase $payer_email. Your total was $".$payment_amount."     for $duration hour 
    with $usercount users.  Previously paid: $paidstatus";

mail ($payer_email , $subject , $message);

眼下$ paidstatus显示为空白电子邮件。我尝试使用的print_r（$ paidstatus），当我有它设置与get_row，它显示了在电子邮件中的“1”，即使数据库值为0。

Answer 1:

是使用get_results作品！我能够访问该变量像这样

$paidstatus = $wpdb->get_results("SELECT paid FROM wp_bbbiller WHERE txn_id = '$txn_id'");

foreach ($paidstatus as $status) {
    $subject = 'Test e-mail';
    $message = "Thank you for your purchase $payer_email. Your total was $".$payment_amount."          for $duration hour 
    with $usercount users.  Previously paid: ".$status->paid;

    mail ($payer_email , $subject , $message);

}

另外get_row也这样工作

    $paidstatus = $wpdb->get_row("SELECT paid FROM wp_bbbiller WHERE txn_id = '$txn_id'");

    $subject = 'Test e-mail';
    $message = "Thank you for your purchase $payer_email. Your total was $".$payment_amount." for $duration hour 
    with $usercount users.  Previously paid: ".$paidstatus->paid;

    mail ($payer_email , $subject , $message);