SQL-ERROR:
SELECT a.id, a.parent_id, a.active, a.name_impressum as name, a.level, a.ordered, a.childs, a.network_id, a.cat_pass, a.markenfilter, a.alter_check, b.name_impressum AS title1, b.parent_id AS parent_id1, b.level as level2, b.ordered as ordered1, b.childs as childs2, a.filter_active, a.mixer_check, a.title_impressum AS titletag FROM shop_categories AS a LEFT OUTER JOIN shop_categories AS b ON a.parent_id = b.id ORDER BY a.level, a.ordered