update users
set count=b.times
from users a
left join (
select uid,count(*) as times from contact group by uid)b
on a.uid=b.uid
set count=b.times
from users a
left join (
select uid,count(*) as times from contact group by uid)b
on a.uid=b.uid
set count=b.times
from users a
inner join (
select uid,count(*) as times from contact group by uid)b
on a.uid=b.uid
set A.count=B.tt
from users A
inner join (
select uid,count(uid) as tt from contact group by uid) B on A.uid=B.uid
update users set [count]=(select count(*) from contact where users.uid=uid)
--方法二
update users set [count]=b.cn from users a join (select uid,cn=count(*) from contact group by uid) b on a.uid=b.uid
(select uid,count=count(uid) from contact group by uid) a
on users.uid=a.uid where name='张三'