นับจำนวนครั้งในเดือนนี้/21 คนไข้ 71558 มีท่อระบายน้ำสมอง r ventricular ระบาย ไม่จำเป็นต้องใช้ตารางทั้งหมด
count the number of times on this month/21 patient 71558 has produced cerebral drain r ventricular drain.It is not neccessary to use all the tables.
 cost:  row_id [ number]  subject_id [ number]  hadm_id [ number]  event_type [ text]  event_id [ number]  chargetime [ time]  cost [ number] 
SELECT COUNT(*) FROM outputevents WHERE outputevents.icustay_id IN (SELECT icustays.icustay_id FROM icustays WHERE icustays.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 71558)) AND outputevents.itemid IN (SELECT d_items.itemid FROM d_items WHERE d_items.label = 'cerebral drain r ventricular drain' AND d_items.linksto = 'outputevents') AND DATETIME(outputevents.charttime, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-0 month') AND STRFTIME('%d', outputevents.charttime) = '21'