表A，B根据id关联，A 表 查询出现次数，根据次数倒叙排名 更新B 表的排名和次数
update B set bcount=a.acount,brank=a.arank
from (select id,count(*)as acount,RANK() over (order by count(*) desc) as arank from A group by id) a where a.id=B.id
rank() 函数用法：RANK() OVER(order by 某列) 根据某列进行排名。