mysql按月、周、天分组查询数据，原始数据是时间戳

如果直接查询单条数据出来 是会卡爆内存的。所以要在mysql内部分好组。
字段upload_time是日期格式时：

select DATE_FORMAT(upload_time,'%Y%u') weeks,count(SN_ID) count from table_sn group by weeks;  -- 按照周分组
select DATE_FORMAT(upload_time,'%Y%m%d') days,count(SN_ID) count from table_sn group by days;  -- 按照日分组 
select DATE_FORMAT(upload_time,'%Y%m') months,count(SN_ID) count from table_sn group by months;  -- 按照月分组

字段upload_time是时间戳数字格式时：

select DATE_FORMAT(FROM_UNIXTIM(upload_time),'%Y%u') weeks,count(SN_ID) count from table_sn group by weeks;  -- 按照周分组
select DATE_FORMAT(FROM_UNIXTIM(upload_time),'%Y%m%d') days,count(SN_ID) count from table_sn group by days;  -- 按照日分组 
select DATE_FORMAT(FROM_UNIXTIM(upload_time),'%Y%m') months,count(SN_ID) count from table_sn group by months;  -- 按照月分组