นับจำนวนผู้ป่วยที่ได้รับการวินิจฉัยว่าเป็นโรค adv eff blood agent โดยไม่จำเป็นต้องใช้ตารางทั้งหมด
count the number of patients who have been diagnosed with adv eff blood agent nec.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 COUNT(DISTINCT admissions.subject_id) FROM admissions WHERE admissions.hadm_id IN (SELECT diagnoses_icd.hadm_id FROM diagnoses_icd WHERE diagnoses_icd.icd9_code = (SELECT d_icd_diagnoses.icd9_code FROM d_icd_diagnoses WHERE d_icd_diagnoses.short_title = 'adv eff blood agent nec'))