Datenbankfehler

SELECT a.*, att.attribute_id, att.attributename, att.attributegroup FROM tbl_article AS a JOIN tbl_article_attributes AS aa USING (article_id) JOIN tbl_attributes AS att USING (attribute_id) WHERE ( a.article_id = '313' ) AND ( at.cms_id = '173' ) AND ( a.public = '1' )

Unknown column 'at.cms_id' in 'where clause'