SQL Query with Concat and Group Concat

group_concat.sql

SELECT
p.product_id,
pd.name,
pd.description,
pd.title_tag AS meta_title,
pd.meta_keywords,
pd.meta_description,
CONCAT('http://www.domain.co.uk/', u.keyword) AS URL,
GROUP_CONCAT(pt.tag) AS tags,
p.status
FROM
product AS p
Left Join product_description AS pd ON pd.product_id = p.product_id
Left Join url_alias AS u ON u.query = CONCAT('product_id=',p.product_id)
Left Join product_tags AS pt ON pt.product_id = p.product_id
GROUP BY p.product_id