ปีนี้มีคนเข้าโรงพยาบาลกี่คน ไม่จำเป็นต้องใช้โต๊ะทั้งหมดนะ
this year how many patients were admitted to the hospital?It is not neccessary to use all the tables.
 d_icd_diagnoses:  row_id [ number]  icd9_code [ text]  short_title [ text]  long_title [ text] 
SELECT COUNT(DISTINCT admissions.subject_id) FROM admissions WHERE DATETIME(admissions.admittime, 'start of year') = DATETIME(CURRENT_TIME(), 'start of year', '-0 year')