WC_Product_Data_Store_CPT::get_starting_sales PHP Method

    public function get_starting_sales()
    {
        global $wpdb;
        return $wpdb->get_col($wpdb->prepare("\n\t\t\tSELECT postmeta.post_id FROM {$wpdb->postmeta} as postmeta\n\t\t\tLEFT JOIN {$wpdb->postmeta} as postmeta_2 ON postmeta.post_id = postmeta_2.post_id\n\t\t\tLEFT JOIN {$wpdb->postmeta} as postmeta_3 ON postmeta.post_id = postmeta_3.post_id\n\t\t\tWHERE postmeta.meta_key = '_sale_price_dates_from'\n\t\t\tAND postmeta_2.meta_key = '_price'\n\t\t\tAND postmeta_3.meta_key = '_sale_price'\n\t\t\tAND postmeta.meta_value > 0\n\t\t\tAND postmeta.meta_value < %s\n\t\t\tAND postmeta_2.meta_value != postmeta_3.meta_value\n\t\t", current_time('timestamp')));
    }