统计数据库内一周数据时用到 yearweek 函数，查询出来的结果与预期值有较大差距， 原来mysql默认 周日当做一周开始，修改成周一当做开始需要在yearweek函数后的model里面填值1即可 ，如下列子：
SELECT referrer_id,COUNT(referrer_id) as num FROM db_distribution WHERE YEARWEEK(datetime,1) = YEARWEEK(now(),1)-1 GROUP BY referrer_id ORDER BY num DESC 