functions.php

<?php

add_shortcode( 'dot_recommended_posts', array( &$this, 'dot_recommended_top_posts' ) );

function dot_recommended_top_posts( $atts, $content = null )
{
    // get our variable from $atts
    $atts = shortcode_atts( array(
        'container' => 'li',
        'number' => '10',
        'post_type' => 'post',
        'year' => '',
        'monthnum' => '',
        'show_count' => '1',
    ), $atts );

    global $wpdb;

	// empty params array to hold params for prepared statement
	$params = array();

	// build query string
	$sql = "SELECT * FROM $wpdb->posts, $wpdb->postmeta WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id";

	// add year
	if( '' !== $atts['year'] ) {
		$sql .= ' AND YEAR(post_date) = %d';
		$params[] = $atts['year'];
	}

	// add monthnum
	if( '' !== $atts['monthnum'] ) {
		$sql .= ' AND MONTH(post_date) = %d';
		$params[] = $atts['monthnum'];
	}

	// add post WHERE
    $sql .= " AND post_status = 'publish' AND post_type = %s AND meta_key = '_recommended'";
	$params[] = $atts['post_type'];

	// add order by and limit
	$sql .= " ORDER BY {$wpdb->postmeta}.meta_value+0 DESC LIMIT %d";
	$params[] = $atts['number'];

	// prepare sql statement
	$query = $wpdb->prepare( $sql, $params );

	// execute query
    $posts = $wpdb->get_results( $query );

    $return = '';


    foreach ($posts as $item) {
        $post_title = stripslashes( $item->post_title );
        $permalink = get_permalink( $item->ID );
        $post_count = $item->meta_value;

        $return .= '<' . esc_html( $atts['container'] ) . '>';
        $return .= '<a href="' . esc_url( $permalink ) . '" title="' . esc_attr( $post_title ) .'" rel="nofollow">' . esc_html( $post_title ) . '</a> ';

        if ( $atts['show_count'] == '1') {
            $return .= '<span class="votes">' . esc_html( $post_count ) . '</span> ';
        }

        //$return .= get_the_post_thumbnail($item->ID, 'showcase-thumbnail');
        $return .= '</' . esc_html( $atts['container'] ) . '>';

    }
    return $return;

}	//dot_recommended_top_posts