sql根据时间戳按年月日分组统计,用于按日期分类：
create_time为时间格式(字段名create_time 根据自己表字段修改,数据库中存为201610071202）
SELECT DATE_FORMAT(create_time,'%Y%u') weeks,COUNT(id) COUNT FROM role GROUP BY weeks;
SELECT DATE_FORMAT(create_time,'%Y%m%d') days,COUNT(id) COUNT FROM role GROUP BY days;
SELECT DATE_FORMAT(create_time,'%Y%m') months,COUNT(id) COUNT FROM role GROUP BY months;
create_time为时间戳格式(字段名create_time 根据自己表字段修改,数据库中存为1474959640）：
SELECT FROM_UNIXTIME(create_time,'%Y%u') weeks,COUNT(id) COUNT FROM role GROUP BY weeks;
SELECT FROM_UNIXTIME(create_time,'%Y%m%d') days,COUNT(id) COUNT FROM role GROUP BY days;
SELECT FROM_UNIXTIME(create_time,'%Y%m') months,COUNT(id) COUNT FROM role GROUP BY months;