統計部分：

按周：select DATE_FORMAT(create_time,'%Y%u') weeks,count(caseid) count from tc_casegroupby weeks;

按日： select DATE_FORMAT(create_time,'%Y%m%d') days,count(caseid) count from tc_casegroupby days;

按月： select DATE_FORMAT(create_time,'%Y%m') months,count(caseid) count from tc_casegroupby months;

去重計算總數

select count(distinct(過濾字段)) from table where ...;

待續