8일차 # 4-21: HAVING clause

  SELECT   department_id, AVG(salary), max(salary)

  FROM     employees

  GROUP BY department_id;

  SELECT   department_id, AVG(salary), max(salary)

  FROM     employees

  GROUP BY department_id

  HAVING   max(salary) > 10000;

  SELECT   department_id, AVG(salary)

  FROM     employees

  GROUP BY department_id

  HAVING   max(salary) > 10000;