create table #temp

(

    id int identity(1,1),

    name varchar(20),

    startYear int,

    startMonth int

)

insert into #temp

select 'z','2010','12' union all

select 'e','2011','11' union all

select 'a','2011','2' union all

select 'b','2011','5' union all

select 'c','2011','10' union all

select 'd','2011','7'

--查询早于等于指定日期的数据

declare @condition varchar(6)

set @condition='201110'

select * from #temp A

where

 (case when LEN(A.startMonth)=1 and A.startMonth!=0 then cast((CAST(startYear as varchar(4))+'0'+cast(A.startMonth as varchar(1))) as date)

       when LEN(A.startMonth)=2 then cast(CAST(startYear as varchar(4))+cast(A.startMonth as varchar(2)) as date) end) <=cast(@condition as date)