select 员工号,sum(数量) as 数量,convert(varchar(10),日期,120) as 日期
from tb
group by 员工号,convert(varchar(10),日期,120)

------解决方案--------------------
SQL code


-- 
-- create table ta (empyeeno varchar(10),qty int,date datetime)



-- insert ta select '1001','2','2009/9/1' union all
-- select '1002','3','2009/9/1' union all
-- select '1001','4','2009/9/1' union all
-- select '1002','2','2009/9/1' union all
-- select '1001','2','2009/9/2' union all
-- select '1002','3','2009/9/2' union all
-- select '1001','4','2009/9/2' union all
-- select '1002','2','2009/9/2'


select * from ta
select empyeeno,sum(qty),date from ta group by empyeeno,date

------解决方案--------------------
SQL code

select 员工号,sum(数量) as 数量,convert(varchar(10),日期,120) as 日期
from tb
group by 员工号,日期