ปีนี้ยาที่จ่ายบ่อยที่สุดสามอันดับแรกสำหรับผู้ป่วยในยุค 50 คืออะไร?ไม่จำเป็นต้องใช้ตารางทั้งหมด
this year, what are the top three most frequently prescribed drugs for patients in the 50s?It is not neccessary to use all the tables.
 treatment:  treatmentid [ number]  patientunitstayid [ number]  treatmentname [ text]  treatmenttime [ time] 
SELECT t1.drugname FROM (SELECT medication.drugname, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM medication WHERE medication.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.age BETWEEN 50 AND 59) AND DATETIME(medication.drugstarttime, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-0 year') GROUP BY medication.drugname) AS t1 WHERE t1.c1 <= 3