1055 Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'slenderc_slenderhk.p.products_model' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
in:
[select distinct p.products_model, pd.products_name, m.manufacturers_name, p.products_quantity, p.products_fsk18, p.products_image, p.products_weight, pd.products_short_description, pd.products_description, p.products_shippingtime, m.manufacturers_id, p.products_id, pd.products_name, p.products_price, p.products_discount_allowed, p.products_tax_class_id from products p left join manufacturers m using(manufacturers_id) left join specials s on p.products_id = s.products_id, products_description pd, categories c, products_to_categories p2c where p.products_status = '1' and p.products_id = pd.products_id and pd.language_id = '1' and p.products_id = p2c.products_id and p2c.categories_id = c.categories_id group by pd.products_name order by pd.products_name limit 0, 20]