create table ta
(
id int,
id_value varchar(30)
)
insert into ta
select 1,'aa,bb' union all
select 2,'aa,bb,cc' union all
select 3,'aaa,bbb,ccc'
select
top 4000 ix = identity(int, 1, 1)
into #tb
from sys.objects a, sys.objects b
select
id,
id_value = substring(id_value,ix,charindex(',',id_value + ',',ix) - ix)
FROM ta as A, #tb as B
WHERE SUBSTRING( ',' + id_value, ix, 1) = ','
drop table ta
drop table #tb