คนไข้รายสุดท้าย 021-155303 เข้าโรงพยาบาลได้อย่างไร?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
how did last patient 021-155303 get admitted to the hospital?It is not neccessary to use all the tables.
 vitalperiodic:  vitalperiodicid [ number]  patientunitstayid [ number]  temperature [ number]  sao2 [ number]  heartrate [ number]  respiration [ number]  systemicsystolic [ number]  systemicdiastolic [ number]  systemicmean [ number]  observationtime [ time] 
SELECT patient.hospitaladmitsource FROM patient WHERE patient.uniquepid = '021-155303' ORDER BY patient.hospitaladmittime DESC LIMIT 1