ผู้ป่วย 18757 จ่ายยาผ่านทาง ih เมื่อใด เป็นครั้งสุดท้ายจนถึง 02/2105?ไม่จำเป็นต้องใช้ตารางทั้งหมด
when was patient 18757 prescribed medication via ih route, for the last time until 02/2105?It is not neccessary to use all the tables.
 inputevents_cv:  row_id [ number]  subject_id [ number]  hadm_id [ number]  icustay_id [ number]  charttime [ time]  itemid [ number]  amount [ number] 
SELECT prescriptions.startdate FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 18757) AND prescriptions.route = 'ih' AND STRFTIME('%y-%m', prescriptions.startdate) <= '2105-02' ORDER BY prescriptions.startdate DESC LIMIT 1