sql server programming: I have table:

ItemId, ItemName, ParentId, FullPath

eg:
1, null, first, first
2, 1, second, first/second
3,2, third, third/second
.... and so on, no limit for depth

now, when i update name of "item", i need to update FullPath of all "item"
's children

How to do it?
Recursion, trigger?
Thank you