ตัวอย่างการทดสอบสี่อันดับแรกที่ได้รับการสั่งซื้อบ่อยที่สุดในปีที่แล้วคืออะไร?ไม่จำเป็นต้องใช้ตารางทั้งหมด
what are the specimen tests top four most frequently ordered in the last year?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 t1.spec_type_desc FROM (SELECT microbiologyevents.spec_type_desc, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM microbiologyevents WHERE DATETIME(microbiologyevents.charttime, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-1 year') GROUP BY microbiologyevents.spec_type_desc) AS t1 WHERE t1.c1 <= 4