instruction: For those employees who was hired before 2002-06-21, visualize a bar chart about the distribution of hire_date and the sum of department_id bin hire_date by weekday, and order by the y-axis in descending.
response: SELECT HIRE_DATE, SUM(DEPARTMENT_ID) FROM employees WHERE HIRE_DATE < '2002-06-21' ORDER BY SUM(DEPARTMENT_ID) DESC