SQL: Recursive Path

Question

Is it possible to create a \"tree resolver\" in SQL?

I have a table:

ID Name Parent
1  a
2  b    1
3  c    1
4  d    3

Now I want a SQL

Answer 1

Suppose we have a simple table called DLFolder with the following columns:

| folderId | name | parentFolderId |

In Oracle you can use the sys_connect_by_path operation.

select fo.folderId as folder_id, sys_connect_by_path(fo.name, '/') as relname
from DLFolder fo
start with fo.parentFolderId=0
connect by prior fo.folderId = fo.parentFolderId

Will give the following result:

/1020_Training_Material
/1020_Training_Material/2000_IBBA
/1020_Training_Material/2000_IBBA/5000_FR
/1020_Training_Material/2000_IBBA/5050_NL

See http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions164.htm