Как по дополнительным полям сделать отбор новостей?

<?php

if (!defined('DATALIFEENGINE')) {
    die("Hacking attempt!");
}

if (isset($_POST['cat_id']) OR isset($_POST['year'])) {

    if ($_POST['cat_id'] == " " || !isset($_POST['cat_id'])) {
        $cat = "";
    } else {
        $cat = "WHERE category=".intval($_POST['cat_id']);
    }

if ($_POST['year'] == " " || !isset($_POST['year'])) {
        $years = "";
    } else {
        $year = intval($_POST['year']);
        if ($_POST['cat_id'] == " " || !isset($_POST['cat_id'])) {
            $years = "WHERE SUBSTRING_INDEX( SUBSTRING_INDEX( xfields, 'year|', -1 ) ,  '||', 1 ) LIKE '%{$year}%'";
        } else {
            $years = "AND SUBSTRING_INDEX( SUBSTRING_INDEX( xfields, 'year|', -1 ) ,  '||', 1 ) LIKE '%{$year}%'";
        }
    }
    

    $paged = intval($config['news_number']);
    $count = $db->query("SELECT id, date, xfields, title, alt_name FROM " . PREFIX . "_post $cat $years LIMIT $paged");
    
        while( $row = $db->get_row($sql_select) ) {
            
            $xfieldsdata = xfieldsdataload( $row['xfields'] );
            $pimg = $xfieldsdata['pimg'];
            $title = $row['title'];
            
            if( $config['allow_alt_url'] ) {
                if( $config['seo_type'] == 1 OR $config['seo_type'] == 2  ) {
                    if( $row['category'] and $config['seo_type'] == 2 ) {
                        $full_link = $config['http_home_url'] . get_url( $row['category'] ) . "/" . $row['id'] . "-" . $row['alt_name'] . ".html";
                    } else {
                        $full_link = $config['http_home_url'] . $row['id'] . "-" . $row['alt_name'] . ".html";
                    }
                } else {
                $full_link = $config['http_home_url'] . date( 'Y/m/d/', $row['date'] ) . $row['alt_name'] . ".html";
                }
            } else {
                $full_link = $config['http_home_url'] . "index.php?newsid=" . $row['id'];
            }
            
            $tpl->load_template('filter_result.tpl');
            $tpl->set( '{full-link}', $full_link );
            $tpl->set( '{title}', $title );
            if ( $pimg ) {
                $tpl->set( '{pimg}', $pimg );
                $tpl->set( '[pimg]', "" );
                $tpl->set( '[/pimg]', "" );
                $tpl->set_block( "'\\[not-pimg\\](.*?)\\[/not-pimg\\]'si", "" );
            } else {
                $tpl->set( '{pimg}', "" );
                $tpl->set( '[not-pimg]', "" );
                $tpl->set( '[/not-pimg]', "" );
                $tpl->set_block( "'\\[pimg\\](.*?)\\[/pimg\\]'si", "" );
            }
            
            $tpl->compile('filter');
            
        }
            $tpl->result['content'] = $tpl->result['filter'];
            $tpl->clear();
        
    
} else {
            $error = "Ошибка";
            $tpl->result['content'] = $error;
            $tpl->clear();
}
?>