select sum(cnt) from 表2 where  sldat between '2011-01-01' and '2012-12-31'

declare @basvipnew table (vipid int,vipname varchar(5),rest int)
insert into @basvipnew
select 1,'tom',0 union all
select 2,'name',1 union all
select 3,'jerry',1

declare @basvipcnt table (vipid int,cnt int,sldat datetime)
insert into @basvipcnt
select 1,5,'2011-03-01' union all
select 1,6,'2011-02-03' union all
select 2,1,'2011-09-08' union all
select 2,10,'2011-11-01' union all
select 3,2,'2011-08-07'

declare @basvipuse table (vipid int,cnt int,sldat datetime)
insert into @basvipuse
select 1,-3,'2011-03-01' union all
select 1,-7,'2011-02-03' union all
select 2,-12,'2011-09-08' union all
select 2,-10,'2011-11-01' union all
select 3,-22,'2011-08-07'

update @basvipnew
set rest=b.cnt+c.cnt from @basvipnew a
left join (select vipid,sum(cnt) as cnt from @basvipcnt 
where sldat between '2011-01-01' and '2011-12-31' group by vipid) b on a.vipid=b.vipid
left join (select vipid,sum(abs(cnt)) as cnt from @basvipuse 
where sldat between '2011-01-01' and '2011-12-31' group by vipid) c on a.vipid=c.vipid

select * from @basvipnew
/*
vipid       vipname rest
----------- ------- -----------
1           tom     21
2           name    33
3           jerry   24
*/

/*
如果正负积分都加的话，用绝对值就ok了。
如果正的是减，负的是加，sum然后求相反数就ok了。
*/