entityMap|blocks|key|48ich|text|php日志中是否有错误？我认为这个问题可能是因为直接使用了$_SESSION['id']+--首先尝试将其创建为一个变量，如下所示|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|dkgbq|$id=$_SESSION['id'];
$stmt->bind_param('s',$id);|code-block|syntax|javascript|2m81g^0|T|F|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|M|9|@$A|N|B|O|C|D]]|E|@]|F|$]]|$2|G|4|H|6|I|8|P|9|@]|E|@]|F|$J|K]]|$2|L|4|-4|6|7|8|Q|9|@]|E|@]|F|$]]]]

Are there errors in the php log? I think the issue might be because of the use of <code>$_SESSION['id']</code> directly - try creating as a variable first like

<pre><code>$id=$_SESSION['id'];
$stmt-&gt;bind_param('s',$id);
</code></pre>

entityMap|blocks|key|21ueh|text|bind_param()需要参数名称或参数索引。所以你应该像这样写代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|9tqn1|$stmt+=+$db->prepare('SELECT+*+FROM+mail+WHERE+userID+=+?+AND+opened+=+0');
$stmt->bind_param(1,$_SESSION['id']);|code-block|syntax|javascript|fra9j|或者|7vaom|$stmt+=+$db->prepare('SELECT+*+FROM+mail+WHERE+userID+=+:user_id+AND+opened+=+0');
$stmt->bind_param(':user_id',$_SESSION['id']);|4ej26^0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|M|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|N|9|@]|A|@]|B|$F|G]]|$2|H|4|I|6|7|8|O|9|@]|A|@]|B|$]]|$2|J|4|K|6|E|8|P|9|@]|A|@]|B|$F|G]]|$2|L|4|-4|6|7|8|Q|9|@]|A|@]|B|$]]]]

The bind_param() needs name of parameter or index of a parameter. So you should write code like this

<pre><code>$stmt = $db-&gt;prepare('SELECT * FROM mail WHERE userID = ? AND opened = 0');
$stmt-&gt;bind_param(1,$_SESSION['id']);
</code></pre>

or

<pre><code>$stmt = $db-&gt;prepare('SELECT * FROM mail WHERE userID = :user_id AND opened = 0');
$stmt-&gt;bind_param(':user_id',$_SESSION['id']);
</code></pre>

entityMap|blocks|key|c0m8a|text|改变|type|unstyled|depth|inlineStyleRanges|entityRanges|data|e5o7s|$msgs+=+'<span+style="color:+yellow;">'.$result->num_rows.'';|code-block|syntax|javascript|8c2al|至|b6tsf|$msgs+=+'<span+style="color:+yellow;">'+.+$msgs+.+'';|2i5ts^0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|M|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|N|9|@]|A|@]|B|$F|G]]|$2|H|4|I|6|7|8|O|9|@]|A|@]|B|$]]|$2|J|4|K|6|E|8|P|9|@]|A|@]|B|$F|G]]|$2|L|4|-4|6|7|8|Q|9|@]|A|@]|B|$]]]]

Change 

<pre><code>$msgs = '&lt;span style="color: yellow;"&gt;'.$result-&gt;num_rows.'&lt;/span&gt;';
</code></pre>

to 

<pre><code>$msgs = '&lt;span style="color: yellow;"&gt;' . $msgs . '&lt;/span&gt;';
</code></pre>

entityMap|blocks|key|3fgpa|text|试试这个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5hscg|$stmt+=+$db->prepare('SELECT+*+FROM+mail+WHERE+userID+=+?+AND+opened+=+0');
++++if($stmt)
++++{
++++++++$stmt->bind_param(1,$_SESSION['id']);
++++++++$stmt->execute();
++++++++$msgs+=+$stmt->num_rows;
++++++++$stmt->close();
++++}

++++if($msgs+>+0)
++++{
++++++++$msgs+=+'<span+style="color:+yellow;">'.$result->num_rows.'';
++++}

++++echo+'+<a+href="mail?id='.$_SESSION['id'].'"><img+src="img/'.$mailico.'"+alt="'.$mailstat.'"+/>+('.$msgs.')</a>';|code-block|syntax|javascript|84ijm^0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|I|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|J|9|@]|A|@]|B|$F|G]]|$2|H|4|-4|6|7|8|K|9|@]|A|@]|B|$]]]]

try this:

<pre><code>$stmt = $db-&gt;prepare('SELECT * FROM mail WHERE userID = ? AND opened = 0');
 if($stmt)
 {
 $stmt-&gt;bind_param(1,$_SESSION['id']);
 $stmt-&gt;execute();
 $msgs = $stmt-&gt;num_rows;
 $stmt-&gt;close();
 }

 if($msgs &gt; 0)
 {
 $msgs = '&lt;span style="color: yellow;"&gt;'.$result-&gt;num_rows.'&lt;/span&gt;';
 }

 echo ' &lt;a href="mail?id='.$_SESSION['id'].'"&gt;&lt;img src="img/'.$mailico.'" alt="'.$mailstat.'" /&gt; ('.$msgs.')&lt;/a&gt;';
</code></pre>

I am currently stumped at the moment as to why a statement I have prepared with PHP is not working properly.

The code is as such:

<pre><code>$stmt = $db-&gt;prepare('SELECT * FROM mail WHERE userID = ? AND opened = 0');
 if($stmt)
 {
 $stmt-&gt;bind_param('s',$_SESSION['id']);
 $stmt-&gt;execute();
 $stmt-&gt;store_result();

 $msgs = $stmt-&gt;num_rows;

 $stmt-&gt;close();
 }

 if($msgs &gt; 0)
 {
 $msgs = '&lt;span style="color: yellow;"&gt;'.$result-&gt;num_rows.'&lt;/span&gt;';
 }

 echo ' &lt;a href="mail?id='.$_SESSION['id'].'"&gt;&lt;img src="img/'.$mailico.'" alt="'.$mailstat.'" /&gt; ('.$msgs.')&lt;/a&gt;';
</code></pre>

Basically, it is supposed to check the database for the table "mail" and see if any PM's have been sent to the logged in user that have not already been opened, and if so, display how many new messages the user has in parenthesis next the the mail icon.

The problem is that when I have an unopened message in the table for that user, it won't update the new message field with the number of message, and is blank (no number at all).

I checked for mysql errors with mysqli_error($db); but nothing came back.

What am I missing, or does it just hate me?

PHP MySQL prepared statement not working

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

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 我现在很困惑，为什么我用PHP编写的一条语句不能正常工作。 代码如下： $stmt = $db->prepare('SELECT * FROM mail WHERE userID = ? AND opened = 0');    if($stmt)    {        $stmt->bind_param('s',...

问PHP MySQL预准备语句不工作
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