Database output not showing. Getting else statement - php

Question

I have the following code that I am not getting any of my db output to appear on my site. I only get the else statement echo response of echo "<p>This topic does not exist.</p>";, but I have topics in my database.
Does anyone see anything in my code that would cause this to not display any output and make the else statement appear? If there isn't, how can I debug this to figure out the issue? I am not getting any errors from my prepared statements, so it has to be within the numrows statement or while loop.
$con = mysqli_connect("localhost", "root", "", "db");
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$cid = $_GET['cid'];
$tid = $_GET['tid'];
$userid = ( isset( $_SESSION['user'] ) ? $_SESSION['user'] : "" );
//Prepared SELECT stmt to get forum topics
$stmt = $con->prepare("SELECT * FROM forum_topics WHERE `category_id`=? AND id=? LIMIT 1");
if ( !$stmt || $con->error ) {
die('Select topics prepare() failed: ' . htmlspecialchars($con->error));
}
if(!$stmt->bind_param('ii', $cid, $tid)) {
die('Select topics bind_param() failed: ' . htmlspecialchars($stmt->error));
}
if(!$stmt->execute()) {
die('Select topics execute() failed: ' . htmlspecialchars($stmt->error));
}
$numrows = $stmt->num_rows;
if($numrows == 1){
echo "<table width='100%'>";
if ( $_SESSION['user'] ) {
echo "<tr><td colspan='2'><input type='submit' value='Add Reply' onClick=\"window.location =
'forum_post_reply.php?cid=".$cid."$tid=".$tid."'\"> <hr />";
} else {
echo "<tr><td colspan='2'><p>Please log in to add your reply</p><hr /></td></tr>";
}
while($row = mysqli_fetch_assoc($stmt)){
//Prepared SELECT stmt to get forum topics
$stmt2 = $con->prepare("SELECT * FROM forum_posts WHERE `category_id`=? AND topic_id=?");
if ( !$stmt2 || $con->error ) {
die('Select topics prepare() failed: ' . htmlspecialchars($con->error));
}
if(!$stmt2->bind_param('ii', $cid, $tid)) {
die('Select topics bind_param() failed: ' . htmlspecialchars($stmt2->error));
}
if(!$stmt2->execute()) {
die('Select topics execute() failed: ' . htmlspecialchars($stmt2->error));
}
while($row2 = mysqli_fetch_assoc($stmt2)){
echo "<tr><td valign='top' style='border: 1px solid #000000;'>
<div style='min-height: 125px;'>".$row['topic_title']."<br />
by ".$row2['post_creator']." - " .$row2['post_date']. "<hr />" . $row2['post_content'] ."</div></td>
<td width='200' valign='top' align='center' style='border: 1px solid #000000;'>User Info Here!</td></tr>
<tr><td colspan='2'><hr /></td></tr>";
}
}
} else {
echo "<p>This topic does not exist.</p>";
}
$cid = $_GET['cid']; is the category id
`$tid = $_GET['tid'];` is another id

Answer 1

To quote the documentation:
Returns the number of rows in the result set. The use of mysqli_stmt_num_rows() depends on whether or not you used mysqli_stmt_store_result() to buffer the entire result set in the statement handle.
The following should do the trick:
$stmt->store_result();
$numrows = $stmt->num_rows;
if ($numrows == 1) {
// etc...