Question

I have the following table structure:

ORGANIZATION_ID   | Name  |  PARENT_ID
--------------------------------------------------
1                 | A     |     0   -Indicates root
2                 | B     |     1
3                 | C     |     2
4                 | D     |     2
5                 | E     |     4
6                 | F     |     1
7                 | G     |     1
8                 | H     |     7
9                 | J     |     8
10                | K     |     9

I am not that great at writing Oracle SQL queries. How can I generate a list of everything (*) child organisation if I pass in a certain Organization ID?

For instance, if I passed in 2, logically I would look for all rows who had a parent ID of 2, then I would recursively look through each of those rows doing the same thing.

I know the logic, how can I recreate that using a sql query in oracle?

Answer 1

CONNECT BY can be used to make this recursive query:

SELECT organization_id, name
FROM t
CONNECT BY PRIOR organization_id = parent_id
START WITH organization_id = 2