ระบุจำนวนผู้ป่วยประเภทการรับเข้าเป็นวิชาเลือกและชื่อการทดสอบในห้องปฏิบัติการคือ asparate aminotransferase (ast) หรือไม่ไม่จำเป็นต้องใช้ตารางทั้งหมด
provide the number of patients whose admission type is elective and lab test name is asparate aminotransferase (ast)?It is not neccessary to use all the tables.
 demographic:  subject_id [ text]  hadm_id [ text]  name [ text]  marital_status [ text]  age [ text]  dob [ text]  gender [ text]  language [ text]  religion [ text]  admission_type [ text]  days_stay [ text]  insurance [ text]  ethnicity [ text]  expire_flag [ text]  admission_location [ text]  discharge_location [ text]  diagnosis [ text]  dod [ text]  dob_year [ text]  dod_year [ text]  admittime [ text]  dischtime [ text]  admityear [ text] 
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN lab ON demographic.hadm_id = lab.hadm_id WHERE demographic.admission_type = "ELECTIVE" AND lab.label = "Asparate Aminotransferase (AST)"