-- выбор id созданных в определенный период студентов, у которых нет занятий и нет записей в истории отмены занятий
WITH students_empty AS (
SELECT students.id from students
  LEFT JOIN classes ON classes.student_id = students.id
  LEFT JOIN users ON users.id = students.parent_id
  WHERE students.created >= '2018-09-12' AND students.created < '2018-09-18' AND users.region_code = 'RU' AND (classes.id IS NULL OR classes.will_deleted IS NOT NULL)
  GROUP BY students.id
),
history_students AS (
  SELECT * FROM classes_cancellation_history WHERE student_id in (SELECT id FROM students_empty)
)
SELECT * FROM students_empty WHERE id NOT IN (SELECT student_id FROM history_students);