oralce -根據日期字段查詢一年中每個月某項的統計數量

 SELECT  
            TO_NUMBER(TO_CHAR (T.POL_START_DATE, 'mm'))getmonth,  
          COUNT (T.POL_CODE)TOTAL  
        FROM  
            IPR_POLICY T  
 
        GROUP BY  
            TO_CHAR (T.POL_START_DATE, 'mm') ORDER BY getmonth