일별 mysql 그룹
GROUP BY DATE_FORMAT(record_date, '%Y%m')
월별 mysql 그룹
select count(*), DATE_FORMAT(timestamp, "%Y-%m-01")
from title
group by DATE_FORMAT(timestamp, "%Y-%m-01")
날짜 별 mysql 그룹
SELECT SUM(foo), DATE(mydate) FROM a_table GROUP BY DATE(a_table.mydate);
일별 mysql 그룹
GROUP BY DATE_FORMAT(created_at, '%Y%m%d')