ในช่วงปีที่แล้ว มีการสั่งจ่าย salmeterol xinafoate diskus (50 mcg) กี่ครั้ง?ไม่จำเป็นต้องใช้ตารางทั้งหมด
how many prescriptions of salmeterol xinafoate diskus (50 mcg) took place during the previous year?It is not neccessary to use all the tables.
 transfers:  row_id [ number]  subject_id [ number]  hadm_id [ number]  icustay_id [ number]  eventtype [ text]  careunit [ text]  wardid [ number]  intime [ time]  outtime [ time] 
SELECT COUNT(*) FROM prescriptions WHERE prescriptions.drug = 'salmeterol xinafoate diskus (50 mcg)' AND DATETIME(prescriptions.startdate, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-1 year')