requête récursive t-sql

Voici un exemple de CTE pour faire cela :

declare @t table (id int, name varchar(max), parentid int)

insert into @t select 1,     'project'  , 0
union all select 2,     'structure' , 1
union all select 3,     'path_1'    , 2
union all select 4,     'path_2'    , 2
union all select 5,     'path_3'    , 2
union all select 6,     'path_4'    , 3
union all select 7,     'path_5'    , 4
union all select 8,     'path_6'    , 5

; with CteAlias as (
    select id, name, parentid
    from @t t
    where t.parentid = 0
    union all
    select t.id, parent.name + '\' + t.name, t.parentid
    from @t t
    inner join CteAlias parent on t.parentid = parent.id
)
select * 
from CteAlias