//테이블 생성

CREATE TABLE `test_st` (
  `reg_date` date NOT NULL,
  `value` int(11) NOT NULL
);
 
INSERT INTO `test_st` (`reg_date`, `value`) VALUES
  ('2017-03-01', 4),
  ('2017-03-08', 2),
  ('2017-03-15', 4),
  ('2017-03-22', 4),
  ('2017-04-01', 9),
  ('2017-04-02', 1),
  ('2017-04-04', 2),
  ('2017-04-09', 4),
  ('2017-04-11', 2),
  ('2017-04-16', 4),
  ('2017-04-18', 5),
  ('2017-04-23', 3),
  ('2017-04-25', 4),
  ('2017-04-30', 4),
  ('2017-04-01', 5);

// 일별통계

SELECT DATE(`reg_date`) AS `date`,
       sum(`value`)
  FROM test_st
 GROUP BY `date`;

//주간통계

SELECT DATE_FORMAT(DATE_SUB(`reg_date`, INTERVAL (DAYOFWEEK(`reg_date`)-1) DAY), '%Y/%m/%d') as start,
       DATE_FORMAT(DATE_SUB(`reg_date`, INTERVAL (DAYOFWEEK(`reg_date`)-7) DAY), '%Y/%m/%d') as end,
       DATE_FORMAT(`reg_date`, '%Y%U') AS `date`,
       sum(`value`)
  FROM test_st
 GROUP BY date;

//월간통계

SELECT MONTH(`reg_date`) AS `date`,
       sum(`value`)
  FROM test_st
 GROUP BY `date`;

//기간별 통계

SELECT DATE(`reg_date`) AS `date`,
       sum(`value`)
  FROM test_st
 WHERE DATE(`reg_date`) >= STR_TO_DATE('2017-04-01', '%Y-%m-%d')
   AND DATE(`reg_date`) <= STR_TO_DATE('2017-04-10', '%Y-%m-%d')
 GROUP BY `date`;