簡單如果else語句不能正常工作

Question

我得到了一個簡單的if else語句，其中我顯示了pdf文件的列表，當id爲空時（又名沒有pdf文件）我想顯示：'沒有可用的下載' 。但是，即使存在pdf文件，也可以顯示文本。

我的代碼：

<div class="widget broucher"> 
    <h4>DOWNLOADS</h4> 
    <ul> 
    <? 
    //pdf bestanden 
    $pdf    = "SELECT * FROM `snm_attachments` WHERE parent_id = '".$conn->real_escape_string($contentcr[0]['id'])."'"; 
    $pdfcon    = $conn->query($pdf); 
    $pdfcr    = array(); 
    while ($pdfcr[]  = $pdfcon->fetch_array()); 

    foreach($pdfcr as $pdf){ 
     if($pdf['id'] != ''){ 
      $downloads .= '<li><a href="cms/attachments/article/'.$contentcr[0]['id'].'/'.$pdf['filename'].' "target="_blank"><i class="fa fa-file-pdf-o"></i>'.$pdf['filename'].'</a></li>'; 
     }else{ 
      $downloads .= '<li>No available downloads</li>'; 
     } 
    } 
    echo $downloads; 
    ?> 
    </ul> 
</div> 

爲什麼總是顯示，即使沒有id目前對於行？

Answer 1

使用此代碼：

<? 
//pdf bestanden 
$pdf    = "SELECT * FROM `snm_attachments` WHERE parent_id = '".$conn->real_escape_string($contentcr[0]['id'])."'"; 
$pdfcon    = $conn->query($pdf); 

// initialize downloads variable: 
$downloads = ''; 

// see how while statement disappears (in your code you have the fetch_array attached to the first element of the array): 
$pdfcr    = $pdfcon->fetch_array(); 

foreach($pdfcr as $pdf){ 
    if($pdf['id'] != ''){ 
     $downloads .= '<li><a href="cms/attachments/article/'.$contentcr[0]['id'].'/'.$pdf['filename'].' "target="_blank"><i class="fa fa-file-pdf-o"></i>'.$pdf['filename'].'</a></li>'; 
    }else{ 
     $downloads .= '<li>No available downloads</li>'; 
    } 
} 
echo $downloads; 
?> 

注比No available downloads消息將在所述數據陣列的所有迭代被渲染時id爲大於空不同。爲了顯示該消息時沒有記錄使用此代碼：

if(count($pdfcr) > 0) { 
    foreach($pdfcr as $pdf){ 
    if($pdf['id'] != ''){ 
     $downloads .= '<li><a href="cms/attachments/article/'.$contentcr[0]['id'].'/'.$pdf['filename'].' "target="_blank"><i class="fa fa-file-pdf-o"></i>'.$pdf['filename'].'</a></li>'; 
    } 
    } 
}