？简单表查询有关问题 ？

？？？简单表查询问题 ？？？
表 T1

name danwei
感康 盒
维C 盒

表 liushui
id name danwei riqi
1 感康 盒 2010-01-01
2 感康 盒 2012-02-15
3 维C 盒 2012-02-18

如何查询出liushui表 2010-01-01 到 2012-02-15 期间段内未包含T1表的其它产品数据，结果为

name danwei
维C 盒


[解决办法]

SQL code

select a.*from t1 a left join liushui b     on a.name = b.name and a.danwei = b.danwei    and b.riqi between '2010-01-01' and '2012-02-15'where b.id is null
[解决办法]
SQL code
declare @t table(name varchar(10),danwei varchar(20))insert into @tselect '感康', '盒' union allselect '维C', '盒' declare @t2 table(id int , name varchar(10), danwei varchar(20), riqi datetime)insert into @t2select 1, '感康','盒','2010-01-01' union allselect 2,'感康', '盒', '2012-02-15' union allselect 3, '维C','盒','2012-02-18'select  distinct b.* from @t2 a,@t b where a.riqi between '2010-01-01' and '2012-02-15' and a.name != b.name