มีผู้ป่วยกี่คนที่วินิจฉัยโรค icd9 รหัส 28803?ไม่จำเป็นต้องใช้ตารางทั้งหมด
how many patients have diagnoses icd9 code 28803?It is not neccessary to use all the tables.
 prescriptions:  subject_id [ text]  hadm_id [ text]  icustay_id [ text]  drug_type [ text]  drug [ text]  formulary_drug_cd [ text]  route [ text]  drug_dose [ text] 
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN diagnoses ON demographic.hadm_id = diagnoses.hadm_id WHERE diagnoses.icd9_code = "28803"