A Database Error Occurred

Error Number: 1054

Unknown column 'function.session' in 'where clause'

SELECT stud2.id FROM students as stud1, students as stud2 WHERE stud1.id = function.session-start AND stud2.folio_status = 'A' AND CONCAT(stud1.first_name, ' ' , stud1.last_name) < CONCAT(stud2.first_name, ' ', stud2.last_name) ORDER BY CONCAT(stud2.first_name, ' ', stud2.last_name) ASC LIMIT 1