นับจำนวนคนไข้เพศ m และประเภทยาเสริมหรือไม่ไม่จำเป็นต้องใช้ทุกตาราง
count the number of patients whose gender is m and drug type is additive?It is not neccessary to use all the tables.
 diagnoses:  subject_id [ text]  hadm_id [ text]  icd9_code [ text]  short_title [ text]  long_title [ text] 
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id WHERE demographic.gender = "M" AND prescriptions.drug_type = "ADDITIVE"