Mysql Error bei Foren-Ansicht

PHP-Code:
<?php

function prefix_info()
{
    return array(
        "name"        => "Prefix-Plugin",
        "description" => "adds a prefix before the thread-subject",
        "website"     => "http://mods.mybboard.net",
        "author"      => "XxAnimusxX",
        "authorsite"  => "http://www.k-under.de",
        "version"     => "1.0",
        "guid"        => "3fb2b1ec27e31aa2b05bb8d444bfda55",
        "compatibility" => "15*"
        );
}

$plugins->add_hook("forumdisplay_thread", "addPrefix_forumdisplay");
$plugins->add_hook("newthread_end", "addPrefix_newthread");
$plugins->add_hook("editpost_end", "addPrefix_editpost");
$plugins->add_hook("editpost_do_editpost_start", "savePrefix_editpost");
$plugins->add_hook("newthread_do_newthread_end", "savePrefix_newthread");

$plugins->add_hook("admin_config_menu", "prefix_toolsmenu");
$plugins->add_hook("admin_config_action_handler", "prefix_actionhandler");


function prefix_toolsmenu($sub_menu)
{
        $sub_menu[] = array(
                      "id" => "prefix",
                      "title" => "Prefix-Manager",
                      "link" => "index.php?module=config/prefix"
                      );
}



function prefix_actionhandler($action)
{
        $action['prefix'] = array('active' => 'prefix', 'file' => 'prefix.php');
}



function prefix_is_installed()
{
        global $db;

        if ($db->field_exists("prefix", "threads"))
        {
                return true;
        }
        return false;
}



function prefix_install()
{
        global $db;

        $db->query("ALTER TABLE ".TABLE_PREFIX."threads ADD prefix VARCHAR(126) NOT NULL");

        $find = preg_quote("{\$gotounread}");
        $replace = "{\$gotounread}{\$thread['prefix']}";
        prefix_replace_templatesets("forumdisplay_thread", $find, $replace);

        $find = preg_quote("trow2\"><input");
        $replace = "trow2\">{\$prefix_menu}<input";
        prefix_replace_templatesets("newthread", $find, $replace);
        prefix_replace_templatesets("editpost", $find, $replace);

        $db->query("CREATE TABLE ".TABLE_PREFIX."prefix (
                           pid INT UNSIGNED NOT NULL AUTO_INCREMENT,
                           title VARCHAR(126) NOT NULL,
                           fid TEXT NOT NULL,
                           gid TEXT NOT NULL,
                           PRIMARY KEY (pid)
        )");
}



function prefix_uninstall()
{
        global $db;

        $db->query("ALTER TABLE ".TABLE_PREFIX."threads DROP prefix");

        $find = preg_quote("{\$gotounread}{\$thread['prefix']}");
        $replace = "{\$gotounread}";
        prefix_replace_templatesets("forumdisplay_thread", $find, $replace);

        $find = preg_quote("trow2\">{\$prefix_menu}<input");
        $replace = "trow2\"><input";
        prefix_replace_templatesets("newthread", $find, $replace);
        prefix_replace_templatesets("editpost", $find, $replace);
        
        
        $db->query("DROP TABLE ".TABLE_PREFIX."prefix");
}



function addPrefix_forumdisplay()
{
        global $thread;

        if ($thread['prefix'])
        {
                $thread['prefix'] = "<strong>[".$thread['prefix']."]</strong> ";
        }
}



function addPrefix_newthread()
{
        global $prefix_menu, $fid;

        $prefix_menu = build_prefixmenu($fid);
}



function addPrefix_editpost()
{
        global $thread, $fid, $pid, $prefix_menu;

        if ($thread['firstpost'] != $pid) return false;
        $prefix_menu = build_prefixmenu($fid, $thread['prefix']);
}



function savePrefix_editpost()
{
        global $mybb, $thread, $db;

        $pid = intval($mybb->input['prefix']);
        if (!$thread['prefix'] && !$pid) return false;

        $prefix = $db->fetch_array($db->simple_select("prefix", "title", "pid=".$pid));

        if (($prefix['title'] == $thread['prefix']) || (!$prefix['title'] && $pid)) return false;
        $db->update_query("threads", array("prefix"=>$prefix['title']), "tid=".$thread['tid']);
}



function savePrefix_newthread()
{
        global $mybb, $db, $tid;

        $pid = intval($mybb->input['prefix']);
        if (!$pid) return false;

        $prefix = $db->fetch_array($db->simple_select("prefix", "title", "pid=".$pid));
        if (!$prefix['title']) return false;

        $db->update_query("threads", array("prefix"=>$prefix['title']), "tid=".$tid);
}



function build_prefixmenu($fid = 0, $selected = "")
{
        global $mybb, $db;
        if (!$fid) return false;

        $query = $db->simple_select("prefix");
        $menu = "";
        while ($prefix = $db->fetch_array($query))
        {
                $checked = "";
                $gids = explode(",", $prefix['gid']);
                $fids = explode(",", $prefix['fid']);

                $group = in_array($mybb->user['usergroup'], $gids);
                if ((in_array($fid, $fids) && $group) || (!$prefix['fid'] && $group))
                {
                        if ($prefix['title'] == $selected) $checked = " selected";
                        $menu.="<option value=\"".$prefix['pid']."\"".$checked.">".$prefix['title']."</option>";
                }
        }

        if ($menu)
        {
                return "<select name='prefix'><option value=\"0\"></option>".$menu."</select> ";
        }
}



function prefix_replace_templatesets($template, $find, $replace)
{
        global $db;

        $query = $db->simple_select("templates", "template, tid", "title='".$template."'");
        while ($template = $db->fetch_array($query))
        {
                $tid = $template['tid']; $body = $template['template'];
                $body = preg_replace("!".$find."!", $replace, $body);

                $db->update_query("templates", array("template" => $db->escape_string($body)), "tid=".$tid);
        }
}

?>