get_posts mit Category&Tags

### Eventsanzeige mit Shortcode im Editor [events num="5" artist="bassekou"] ###
function split_events($atts, $content = null) {
        extract(shortcode_atts(array(
                "num" => '5',
                "artist" => ''
        ), $atts));
        global $post;
        $myposts = get_posts('numberposts='.$num.'&order=DESC&orderby=post_date&category=27&tag='.$artist);
        $retour='<ul>';
        foreach($myposts as $post) :
             setup_postdata($post);
             #$retour.='<li><a href="'.get_permalink().'">'.the_title("","",false).'</a></li>';
             $retour.='<li>'.the_title("","",false).'</li>';
             $retour.='<li><a href="'.get_permalink().'">'.get_the_excerpt("",true,"").'</a></li>';
        endforeach;
        $retour.='</ul> ';
        return $retour;
}
add_shortcode( "events", "split_events");