update products set main_image_id = (
select id as image_id from images where
  owner_type = 'Product' and owner_id = products.id and main = true
  limit 1
)


update products set main_category_id = (
SELECT min(category_id) FROM category_products where product_id=products.id
group by product_id
)

update product_vendors set main_category_id = (
SELECT min(category_id) FROM category_product_vendors where product_vendor_id=product_vendors.id
group by product_vendor_id
)

DELETE cl FROM category_languages cl
INNER JOIN (
  select max(id) AS id, count(*) AS count from category_languages group by category_id, locale
) duplicates
ON (cl.id = duplicates.id AND duplicates.count > 1);