ค้นหาผู้ป่วยอายุน้อยกว่า 64 ปี ด้วยขั้นตอน icd9 รหัส 4311 ไม่จำเป็นต้องใช้ทุกตาราง
Find the patients aged less than 64 years old with procedure icd9 code 4311.It is not neccessary to use all the tables.
 demographic:  subject_id [ text]  hadm_id [ text]  name [ text]  marital_status [ text]  age [ text]  dob [ text]  gender [ text]  language [ text]  religion [ text]  admission_type [ text]  days_stay [ text]  insurance [ text]  ethnicity [ text]  expire_flag [ text]  admission_location [ text]  discharge_location [ text]  diagnosis [ text]  dod [ text]  dob_year [ text]  dod_year [ text]  admittime [ text]  dischtime [ text]  admityear [ text] 
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.age < "64" AND procedures.icd9_code = "4311"