Oracle HR on Rails

Rails
#1

Interesting read…apologies if it has been posted already.

http://www.oracle.com/technology/pub/articles/saternos-rails.html

#2

Interesting read…apologies if it has been posted already.

Yes

Oracle staff seem to ignore some of the jewels of Ror like act_as_tree :

Quote

The query to construct the corporate hierarchy is as follows:

SELECT tree.,
LEAD (hierarchy_level) OVER (ORDER BY seq) next_level
FROM (
SELECT CONNECT_BY_ROOT last_name top_node_name,
(last_name || ‘, ’ || first_name ||’ (’||job_title||’)’)
employee_name,
emp.id employee_id,
SYS_CONNECT_BY_PATH (last_name, ‘->’) node_path,
LEVEL hierarchy_level,
ROWNUM seq
FROM(
SELECT e., j.job_title
FROM employees e, jobs j
WHERE e.job_id = j.id
) emp
START WITH emp.job_title= ‘President’
CONNECT BY PRIOR emp.id = manager_id
ORDER SIBLINGS BY emp.id
) tree
ORDER BY seq

#3

I expect nothing less from Oracle… lots of proprietary SQL, poor
documentation, and lots of product plugs.

:slight_smile:

#4

On 7/6/06, Mathieu C. [email protected] wrote:

                    (last_name || ', ' || first_name ||' ('||job_title||')') employee_name,
     CONNECT BY PRIOR emp.id = manager_id
     ORDER SIBLINGS BY emp.id
     ) tree

ORDER BY seq

Oracle has special syntax (CONNECT BY) for selecting tree-like data
efficiently a single query, something I don’t think acts_as_tree
doesn’t make use of (and I’m too lazy to check). An oracle only
version of acts_as_tree could be made much more efficient than the
generic database version.

Tom

#5

Tom W. wrote:

Oracle has special syntax (CONNECT BY) for selecting tree-like data
efficiently a single query, something I don’t think acts_as_tree
doesn’t make use of (and I’m too lazy to check). An oracle only
version of acts_as_tree could be made much more efficient than the
generic database version.

Yep. In some cases the proprietary approach actually does make sense.
Might as well get some value out of all that $$$.