I try to get more than 3 feed from other web site and show it in my site like :

    function fw_shortcode( $atts ) 
    	global $wpdb ,$feedtable;
    	$result=mysql_query("SELECT * FROM ".$feedtable." ORDER BY RAND() LIMIT 3");
     $rss = fetch_feed($row["weburl"]);
     if (!is_wp_error( $rss ) ) : 
        $maxitems = $rss->get_item_quantity(1);
        $rss_items = $rss->get_items(0, $maxitems);
        foreach ( $rss_items as $item ) :
    $code .= '<article class="col-md-4 col-sm-6 col-xs-12" itemscope="" itemtype="http://schema.org/BlogPosting">
    <div class="vendoritem">';
    $code .= '<a href="'.esc_url( $item->get_permalink() ).'"  target='."_blank".'>';
    $code .= '<img width="300" height="225" src="' .get_first_image_url($item->get_description()). '" class="img-responsive relat wp-post-image" style="background-color:#3498db;">';
    $code .= '</a>
    <div class="vendoritem__details">
    <a href="'.esc_url( $item->get_permalink() ).'" class="vendoritem__title" target='."_blank".'>
    '.esc_html( $item->get_title() ).'</a>
    /* End Loop */
    $code .= '</div>';
    return $code;

My problem is i need to shoe only random 3 feed from table. but **some time** show me 2 feed, Why !!, and if any feed not work, how can get other feed from DB