ครั้งแรกที่โรงพยาบาลแห่งนี้พบผู้ป่วย 94229 ได้รับการสั่งยาหรือไม่ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
when was the first time in this hospital encounter patient 94229 was prescribed a medication?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 prescriptions.startdate FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 94229 AND admissions.dischtime IS NULL) ORDER BY prescriptions.startdate LIMIT 1