wp e-commerce group product by category [closed]

You are very close. I had the same problem a while ago, and blogged about it. Your join is missing one more join table, wp_terms, which has the term you want to sort on.

Here is the code I used:

class OrderWpscProducts {

    // flag for when a shop products post query is being created
    private $isProductQuery = false;

    public function __construct() {
        // hooks for altering order of product pages
        add_filter('parse_query', array($this, 'filterProductQueryMark'), 20);
        add_filter('posts_join', array($this, 'filterProductQueryJoins'), 20);
        add_filter('posts_orderby', array($this, 'filterProductQueryOrderBy'), 20);
    }

    /**
    * detect a posts query that should return a list of shop products, 
    * and mark it for later filters
    * @param WP_Query $query
    * @return WP_Query
    */
    public function filterProductQueryMark($query) {
        $this->isProductQuery = false;

        if (!is_admin() && (wpsc_is_in_category() || !empty($query->query_vars['wpsc_wine_style']))) {
            $this->isProductQuery = true;
        }
    }

    /**
    * if the posts query is for a list of shop products, 
    * then add some tables to the join so that we can sort by category name
    * @param string $joins
    * @return string
    */
    public function filterProductQueryJoins($joins) {
        global $wpdb;

        if ($this->isProductQuery) {
            $joins .= "
 INNER JOIN $wpdb->term_relationships wpsc_cat_rel ON wp_posts.ID = wpsc_cat_rel.object_id
 INNER JOIN $wpdb->term_taxonomy wpsc_cat_tax ON wpsc_cat_tax.term_taxonomy_id = wpsc_cat_rel.term_taxonomy_id
   and wpsc_cat_tax.taxonomy = 'wpsc_product_category'
 INNER JOIN $wpdb->terms wpsc_cat ON wpsc_cat.term_id = wpsc_cat_tax.term_id
";
        }

        return $joins;
    }

    /**
    * if the posts query is for a list of shop products, then sort by category name and product title
    * @param string $orderby
    * @return string
    */
    public function filterProductQueryOrderBy($orderby) {
        if ($this->isProductQuery) {
            $orderby = 'wpsc_cat.name ASC, wp_posts.post_title ASC';
        }

        return $orderby;
    }
}

// create instance, will be kept alive by hooks
new OrderWpscProducts();