สี่ขั้นตอนที่ได้รับบ่อยที่สุดสำหรับผู้ป่วยที่มีอายุ 30 ปีคืออะไร?ไม่จำเป็นต้องใช้ตารางทั้งหมด
what are the four most commonly given procedures for patients who have an age 30s?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 d_icd_procedures.short_title FROM d_icd_procedures WHERE d_icd_procedures.icd9_code IN (SELECT t1.icd9_code FROM (SELECT procedures_icd.icd9_code, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM procedures_icd WHERE procedures_icd.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.age BETWEEN 30 AND 39) GROUP BY procedures_icd.icd9_code) AS t1 WHERE t1.c1 <= 4)