ค่ารักษาล่าสุดเท่าไหร่คะ?ไม่จำเป็นต้องใช้ทุกตารางค่ะ
How much does the most recent treatment cost?It is not neccessary to use all the tables.
 Treatments:  (cost_of_treatment [ VARCHAR ] date_of_treatment [ VARCHAR) ]
SELECT cost_of_treatment FROM Treatments ORDER BY date_of_treatment DESC LIMIT 1