มีใบสั่งยากี่รายการตั้งแต่ 2 ปีที่แล้วสำหรับแอสไพรินชนิดเคี้ยว 81 มก.?ไม่จำเป็นต้องใช้ทุกตาราง
how many prescriptions was prescribed since 2 years ago for aspirin 81 mg chewable tablet?It is not neccessary to use all the tables.
 patient:  uniquepid [ text]  patienthealthsystemstayid [ number]  patientunitstayid [ number]  gender [ text]  age [ text]  ethnicity [ text]  hospitalid [ number]  wardid [ number]  admissionheight [ number]  admissionweight [ number]  dischargeweight [ number]  hospitaladmittime [ time]  hospitaladmitsource [ text]  unitadmittime [ time]  unitdischargetime [ time]  hospitaldischargetime [ time]  hospitaldischargestatus [ text] 
SELECT COUNT(*) FROM medication WHERE medication.drugname = 'aspirin 81 mg chewable tablet' AND DATETIME(medication.drugstarttime) >= DATETIME(CURRENT_TIME(), '-2 year')