ยาที่จ่ายบ่อยที่สุดสามอันดับแรกสำหรับผู้ป่วยอายุ 30 ปีในปีนี้คืออะไร? ไม่จำเป็นต้องใช้ตารางทั้งหมด
what are the top three most frequently prescribed drugs for patients aged 30s this year?It is not neccessary to use all the tables.
 icustays:  row_id [ number]  subject_id [ number]  hadm_id [ number]  icustay_id [ number]  first_careunit [ text]  last_careunit [ text]  first_wardid [ number]  last_wardid [ number]  intime [ time]  outtime [ time] 
SELECT t1.drug FROM (SELECT prescriptions.drug, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.age BETWEEN 30 AND 39) AND DATETIME(prescriptions.startdate, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-0 year') GROUP BY prescriptions.drug) AS t1 WHERE t1.c1 <= 3