How do I create a recursive query in MSSQL 2005?

Question

Let\'s say I have the following table:

CustomerID ParentID Name
========== ======== ====
1          null     John
2          1        James
3          2        J         


        

Answer 1

On SQL Server 2005 you can use CTEs (Common Table Expressions) :

with Hierachy(CustomerID, ParentID, Name, Level)
as
(
select CustomerID, ParentID, Name, 0 as Level
    from Customers c
    where c.CustomerID = 2 -- insert parameter here
    union all
    select c.CustomerID, c.ParentID, c.Name, ch.Level + 1
    from Customers c
    inner join Hierachy ch
    on c.ParentId = ch.CustomerID
)
select CustomerID, ParentID, Name
from Hierachy
where Level > 0