Word Count Query

[Dirks]

Hey everyone, I run a creative writing website that rewards people by number of words written rather than posts. I'm trying to come up with a rudimentary webpage that searches word count in a thread with a mySQL query. By searching online, my coder and I have hacked together what appears on paper to be a workable code, but it still produces a database error when the query is made. I was hoping someone here could help me out.

Here's the code:

<?php
require_once('./global.php');
error_reporting(E_ALL & ~E_NOTICE & ~8192);

// define variables and set to empty values
$threadID = $threadIDErr = "";
$totalWords = 0;

if ($_SERVER["REQUEST_METHOD"] == "POST") {
   if (empty($_POST["threadID"])) {
     $threadIDErr = "threadID is required";
   } else {
     $threadID = test_input($_POST["threadID"]);
     // check if threadID only contains numbers
     if (!preg_match("/^[1-9]+$/",$name)) {
       $threadIDErr = "Only numbers allowed"; 
     }
   }
   
   // fetch all post from a specfic thread
   $posts = $vbulletin->db->query_read("
       SELECT pagetext 
   	   FROM " . TABLE_PREFIX . "post 
   	   WHERE threadid = $threadid
   ");
   
   while ($post = $vbulletin->db->fetch_array($posts)) {
      $totalWords = $totalWords + str_word_count($post['pagetext']);
   }
}

function test_input($data) {
   $data = trim($data);
   $data = stripslashes($data);
   $data = htmlspecialchars($data);
   return $data;
}
?>

<h2>Thread Word Count</h2>
<p><span class="error">* required field.</span></p>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> 
   Thread ID: <input type="text" name="threadID" value="<?php echo $threadID;?>">
   <span class="error">* <?php echo $threadIDErr;?></span>
   <br><br>
   <input type="submit" name="submit" value="Submit"> 
</form>

<?php
echo sprintf("Thread ID %i contains %s words", $threadID, vb_number_format($totalWords));
?>

Here's the error I'm getting:

Database error in vBulletin 4.2.2:

Invalid SQL:

       SELECT pagetext 
   	   FROM post 
   	   WHERE threadid =;

MySQL Error   : You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 3
Error Number  : 1064

Any help you can provide would be great. Here's the sample: www.althanas.com/world/postcount.php