นับจำนวนคนไข้ที่วินิจฉัยชื่อสั้นว่า dermatitis nos และ test liquid คือปัสสาวะหรือไม่ ไม่จำเป็นต้องใช้ตารางทั้งหมด
count the number of patients whose diagnoses short title is dermatitis nos and lab test fluid is urine?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 diagnoses ON demographic.hadm_id = diagnoses.hadm_id INNER JOIN lab ON demographic.hadm_id = lab.hadm_id WHERE diagnoses.short_title = "Dermatitis NOS" AND lab.fluid = "Urine"