A Database Error Occurred

Error Number: 1054

Unknown column 'tour' in 'where clause'

SELECT o.obj_id,cat.alias as type, city.alias as city, city2.alias as pCity FROM nxm_cat_obj o, nxm_cat_cat cat,nxm_cities city, nxm_cities city2 where o.cat_id= cat.cat_id and o.city_id=city.city_id and ((city.parent_id = 0 and city2.city_id = o.city_id) or city2.city_id=city.parent_id ) and o.obj_id = tour