Question

以下代码导致我正在处理的页面返回空白页面。页面上还有其他代码可以返回内容，如果我注释掉下面的代码，它会发生。下面的代码中是否有任何错误？

提前致谢，

约翰

$querysub = mysql_query("SELECT subcheck FROM submission WHERE submissionid = $submissionid");
$result = mysql_query($querysub);
if (!$result) {
    die 'Could not run query: ' . mysql_error();
}
else{
$subcheck = mysql_result($result, 0);
}

if($uid = $submittor)
{

if($subcheck = 1)
{

echo '<div class="commentnotify">You submitted item story and you have chosen to receive emails when someone comments on it.<a href="http://www...com/.../comments/commentnotifystop.php?submission='.urlencode($row["title"]).'&submissionid='.$row["submissionid"].'&url='.$row["url"].'&countcomments='.strtoupper($row["countComments"]).'&submittor='.$row["username"].'&submissiondate='.$row["datesubmitted"].'&dispurl='.$row["displayurl"].'">Click here to stop.</a></div>';


} else {
   echo '<div class="commentnotify">You submitted this item and you have chosen not to receive emails when someone comments on it.<a href="http://www...com/.../comments/commentnotifystart.php?submission='.urlencode($row["title"]).'&submissionid='.$row["submissionid"].'&url='.$row["url"].'&countcomments='.strtoupper($row["countComments"]).'&submittor='.$row["username"].'&submissiondate='.$row["datesubmitted"].'&dispurl='.$row["displayurl"].'">Click here to start.</a></div>';


} else {

}

Answer 1

您在=条件中指定了分配运算符if，而您需要comparison operator（==）：

if($uid = $submittor)

应该是：

if($uid == $submittor)

和

if($subcheck == 1)

此行之后您还缺少结束括号}：

echo '<div class="commentnotify">You submitted this item and you have chosen not to receive emails when someone comments on it.<a href="http://www...com/.../comments/commentnotifystart.php?submission='.urlencode($row["title"]).'&submissionid='.$row["submissionid"].'&url='.$row["url"].'&countcomments='.strtoupper($row["countComments"]).'&submittor='.$row["username"].'&submissiondate='.$row["datesubmitted"].'&dispurl='.$row["displayurl"].'">Click here to start.</a></div>';

Answer 2

您不能拥有两个else块。但我想在这种情况下嵌套只是一个问题：

if($uid = $submittor)
{
    if($subcheck = 1)
    {
        echo '<div class="commentnotify">You submitted item story and you have chosen to receive emails when someone comments on it.<a href="http://www...com/.../comments/commentnotifystop.php?submission='.urlencode($row["title"]).'&submissionid='.$row["submissionid"].'&url='.$row["url"].'&countcomments='.strtoupper($row["countComments"]).'&submittor='.$row["username"].'&submissiondate='.$row["datesubmitted"].'&dispurl='.$row["displayurl"].'">Click here to stop.</a></div>';
    } else {
       echo '<div class="commentnotify">You submitted this item and you have chosen not to receive emails when someone comments on it.<a href="http://www...com/.../comments/commentnotifystart.php?submission='.urlencode($row["title"]).'&submissionid='.$row["submissionid"].'&url='.$row["url"].'&countcomments='.strtoupper($row["countComments"]).'&submittor='.$row["username"].'&submissiondate='.$row["datesubmitted"].'&dispurl='.$row["displayurl"].'">Click here to start.</a></div>';

    }  // <-- added this one
} else {

}

顺便说一下：您使用的是assignment operator =，而不是像==这样的comparison operator。赋值运算符生成指定的值。因此，表达式$uid = $submittor返回$submittor的值，$subcheck = 1返回1。

Answer 3

它缺少if（$ uid = $ submittor）{...}的最后一个括号。然后你收到一个错误，但你的服务器似乎无法显示它们，显示一个空白页面。

导致内容页面内容消失的代码

3 个答案: