求在两表中统计各数的语名
declare @t1 table(
id int,
groupid int,
name varchar(10))
insert into @t1 (id,groupid,name)values(0,0,'A')
insert into @t1 (id,groupid,name)values(1,2,'C')
insert into @t1 (id,groupid,name)values(2,2,'B')
insert into @t1 (id,groupid,name)values(3,3,'R')
insert into @t1 (id,groupid,name)values(4,3,'R')
insert into @t1 (id,groupid,name)values(5,2,'R')
select * from @t1

declare @t2 table(
groupid int,
groupname varchar(10))
insert into @t2(groupid,groupname) values(2,'GroupA')
insert into @t2(groupid,groupname) values(3,'GroupB')
insert into @t2(groupid,groupname) values(4,'GroupV')
select * from @t2

-----所要的结果-----
groupid groupname count
 2 GroupA 3
 3 GroupB 2
 4 GroupV 0

------解决方案--------------------

SQL code

select
  a.groupid,b.groupname,isnull(count(1),0) as [count] 
from
  @t1 a join @t2 b 
on
  a.groupid=b.groupid
group by
  a.groupid,b.groupname