ขั้นตอนใดบ้างที่สี่อันดับแรกได้รับมากที่สุดในปีที่แล้ว?ไม่จำเป็นต้องใช้ตารางทั้งหมด
what are the procedures that are the top four most commonly received in the last year?It is not neccessary to use all the tables.
 treatment:  treatmentid [ number]  patientunitstayid [ number]  treatmentname [ text]  treatmenttime [ time] 
SELECT t1.treatmentname FROM (SELECT treatment.treatmentname, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM treatment WHERE DATETIME(treatment.treatmenttime, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-1 year') GROUP BY treatment.treatmentname) AS t1 WHERE t1.c1 <= 4