1054 - Unknown column 'z1' in 'where clause'

select p.products_fsk18, p.products_shippingtime, s.specials_new_products_price, s.expires_date, s.specials_quantity, p.products_model, p.products_ean, pd.products_name, m.manufacturers_name, mi.default_delivery, p.products_quantity, p.products_image, p.products_weight, pd.products_short_description, pd.products_description, p.products_id, p.manufacturers_id, p.products_price, p.products_price_extra, p.products_vpe, p.products_vpe_status, p.products_vpe_value, p.products_discount_allowed, p.products_tax_class_id, p.products_quantity_stock, p.products_quantity_shop, p.products_quantity_ordered, p.free_shipping from products_description pd, products_to_categories p2c, products p left join manufacturers m on p.manufacturers_id = m.manufacturers_id left join specials s on p.products_id = s.products_id and s.status = 1 AND s.specials_id IN (SELECT s.specials_id FROM specials s LEFT JOIN specials_to_zones sz ON s.specials_id = sz.specials_id WHERE s.products_id = p.products_id AND (sz.zone_id IN (1, 1) OR sz.zone_id IS NULL)) left join manufacturers_info mi on m.manufacturers_id = mi.manufacturers_id where p.products_status = '1'and p.products_id = p2c.products_id and pd.products_id = p2c.products_id and pd.language_id = '3' and p2c.categories_id in ( z1) ORDER BY pd.products_name

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