tricor ราคาเท่าไหร่?ไม่จำเป็นต้องใช้ทุกตาราง
tricor what is the price?It is not neccessary to use all the tables.
 patients:  row_id [ number]  subject_id [ number]  gender [ text]  dob [ time]  dod [ time] 
SELECT DISTINCT cost.cost FROM cost WHERE cost.event_type = 'prescriptions' AND cost.event_id IN (SELECT prescriptions.row_id FROM prescriptions WHERE prescriptions.drug = 'tricor')