谁能帮我写这个sql语句啊？

[jiang10000]

字段名：
intime outtime begstation carnum type gross
2004-01-20 2004-01-25 ss 1 玉米 20
2004-01-20 2004-01-26 ss 1 玉米 10
2004-01-21 2004-01-30 ss 1 玉米 30
我想统计出1月份总共有多少车皮出库，因为第一二是同一个车皮分两次出库，所以只能算一个车皮，那么统计出来的数据就应该是2，我现在就是想请教一下这个sql语句该怎么写呢？只有intime和carnum才能唯一确定一个车皮.

[伍子V5]

select count(1) count from tablename group by intime,carnum

select sum(gross) gross from tablename group by intime,carnum

[愉快的登山者]

select sum(1) from
(select distinct intime, carnum from tablename) as A

[1ssp]

你试试!
select a.intime,a.type ,num=sum(carnum) from
(select distinct intime ,type,carnum from tablename) a
group by a.intime,a.type

[leeboyan]

看不太懂：
select carnum into table2 from table1 group by carnum where month(outtime)=1
select count(carnum) from table2
drop table table2

[1ssp]

不好意思,上面的有的问题!
create table t1
(intime datetime, outtime datetime, carnum int, type char(10))
go
insert into t1 values('2004-01-20', '2004-01-25', 1, '玉米')
insert into t1 values('2004-01-20', '2004-01-25', 1, '玉米')
insert into t1 values('2004-01-21', '2004-01-25', 1, '玉米')
select num=sum(carnum) from
(select distinct intime ,type,carnum from t1) a

go
drop table t1

num
-----------
2

（所影响的行数为 1 行）

[ufan]

select intime,carnum,count(*) from tablename group by intime,carnum where DATEPART(month,outtime) = 1

[ufan]

上一语句写错一点，应如下：
select intime,carnum,count(*) from tablename where DATEPART(month,outtime) = 1 group by intime,carnum