Needing Help For Sql Script

[galleriaaurea]

hi,
i'm writing this script trying to export main data of my shop's items:

SELECT 
a.`id_product`, b.`name` AS `name`, `reference`, 
sav.`quantity` AS `quantita`, 
a.`wholesale_price` AS `costo`, 
a.`price` AS `price`, 
b.description_short,
b.description,
---- >  GROUP_CONCAT(DISTINCT(xz.name) SEPARATOR ",") as categories,
a.`id_manufacturer` AS `manufacturer`, 
a.`id_supplier` AS `supplier`, 
sa.`active` AS `active` , shop.`name` AS `shopname`, 
a.`id_shop_default`, 
image_shop.`id_image` AS `id_image`, 
sa.`price`, 0 AS `price_final`, 
a.`is_virtual`, pd.`nb_downloadable`, 
sa.`active`, IF(sav.`quantity`<=0, 1, 0) AS `badge_danger` 
FROM `ps_product` a 
LEFT JOIN `ps_product_lang` b ON (b.`id_product` = a.`id_product` AND b.`id_lang` = 2 AND b.`id_shop` = 1) 
LEFT JOIN `ps_stock_available` sav ON (sav.`id_product` = a.`id_product` AND sav.`id_product_attribute` = 0 AND sav.id_shop = 1 AND sav.id_shop_group = 0 ) 
JOIN `ps_product_shop` sa ON (a.`id_product` = sa.`id_product` AND sa.id_shop = a.id_shop_default) 
---- > LEFT JOIN `ps_category_product` xp ON (a.`id_product` = xp.`id_product`)
---- > LEFT JOIN `ps_category_lang` xz ON (xp.`id_category` = xz.`id_category`)
LEFT JOIN `ps_shop` shop ON (shop.id_shop = a.id_shop_default) 
LEFT JOIN `ps_image_shop` image_shop ON (image_shop.`id_product` = a.`id_product` AND image_shop.`cover` = 1 AND image_shop.id_shop = a.id_shop_default) 
LEFT JOIN `ps_image` i ON (i.`id_image` = image_shop.`id_image`) LEFT JOIN `ps_product_download` pd ON (pd.`id_product` = a.`id_product`) 
WHERE 1 AND b.`name` LIKE '%pizza%' ORDER BY a.`id_product` ASC LIMIT 0, 50

Well... without the lines with the "---- >" all works well (the "---- > " is used only to tell you which ones, of course...)
Adding that 3 lines i can read also the CATEGORIE LIST, but ONLY FOR THE FIRST PRODUCT.
WHY?

2nd. question: how to exctract image url instead of image id, please?

Thank you all

Edited January 29, 2016 by galleriaaurea (see edit history)