นับจำนวนผู้ป่วยที่ได้รับยาเฮปาริน ฟลัช ฮิคแมน (100 ยูนิต/มล.) ตั้งแต่ปี 2101 ไม่จำเป็นต้องใช้ทุกตาราง
count the number of patients who had been prescribed an heparin flush hickman (100 units/ml) since 2101.It is not neccessary to use all the tables.
 admissions:  row_id [ number]  subject_id [ number]  hadm_id [ number]  admittime [ time]  dischtime [ time]  admission_type [ text]  admission_location [ text]  discharge_location [ text]  insurance [ text]  language [ text]  marital_status [ text]  ethnicity [ text]  age [ number] 
SELECT COUNT(DISTINCT admissions.subject_id) FROM admissions WHERE admissions.hadm_id IN (SELECT prescriptions.hadm_id FROM prescriptions WHERE prescriptions.drug = 'heparin flush hickman (100 units/ml)' AND STRFTIME('%y', prescriptions.startdate) >= '2101')