尝试从数据库中 _GET 数据时 SQL 语句失败

如何解决尝试从数据库中 _GET 数据时 SQL 语句失败

尝试从数据库获取数据时，stmt 失败。在同一个文件中使用类似的类型代码从其他数据库中获取数据，它工作正常。它与“线程猫”是数据库中的外键这一事实有关吗？

<?PHP
        $catname = $_GET['cat'];
        $sql = "SELECT * FROM `threads` WHERE thread-cat=?;";
        $stmt = MysqLi_stmt_init($conn);
        if (!MysqLi_stmt_prepare($stmt,$sql)){
            echo "sql stmt Failed";
        } else {
            MysqLi_stmt_bind_param($stmt,"s",$catname);
            MysqLi_stmt_execute($stmt);
            $result = MysqLi_stmt_get_result($stmt);
            
            while($row = MysqLi_fetch_assoc($result)){
                $id = $row['thread-id'];
                $title = $row['thread-title'];
                $content = $row['thread-content'];
                $timestamp = $row['timestamp'];
 
    
            echo '<tr>
                <td class="tg-0pky"><img src="https://via.placeholder.com/32x32"></td>
                <td class="tg-0pky"><b><a href="">'.$title.'</a></b><br>by <a href="">(User)</a> - (Date created)</td>
                <td class="tg-0pky">(Reply count)</td>
                <td class="tg-0pky">by <a href="">(User)</a><br>(Date Last Post)</td>
              </tr>';
            }
        }
    ?>