WordPress database error: [Unknown column 'r.int_designation' in 'SELECT']SELECT at.int_staff, at.int_meeting, s.an_staff, s.int_wp_id, CONCAT(tl.txt_title,' ', s.txt_forename,' ',s.txt_surname) AS txt_staff, r.an_role, r.txt_role, r.int_designation FROM tbl_attendee AS at INNER JOIN tbl_staff AS s ON at.int_staff = s.an_staff INNER JOIN tbl_title AS tl ON s.int_title = tl.an_title INNER JOIN tbl_role AS r ON s.int_role = r.an_role WHERE at.int_meeting = 29 ORDER BY r.int_designation, s.an_staff