Oracle 按日期统计

---------------按日期统计-----------------------------------------------------
--按照星期进行统计
SELECT TO_CHAR(SYSDATE, 'day') FROM DUAL GROUP BY TO_CHAR(SYSDATE, 'day');

--按照每周进行统计
SELECT TO_CHAR(SYSDATE, 'ww') FROM DUAL GROUP BY TO_CHAR(SYSDATE, 'ww');

--按照每月进行统计
SELECT TO_CHAR(SYSDATE, 'mm') FROM DUAL GROUP BY TO_CHAR(SYSDATE, 'mm');

--按照每季度进行统计
SELECT TO_CHAR(SYSDATE, 'q') FROM DUAL GROUP BY TO_CHAR(SYSDATE, 'q');

--按照每年进行统计
SELECT TO_CHAR(SYSDATE, 'yyyy')
  FROM DUAL
 GROUP BY TO_CHAR(SYSDATE, 'yyyy');