Need to find out the hierarchy information of a particular Menu

Question

I have written a query using "select ... start with initial-condition connect by recurse-condition" syntax to get the Hierarchical information for a prticular menu.
select count(SUB_MENU_ID) from FND_MENU_ENTRIES_VL
start with MENU_ID = 76580
and SUB_MENU_ID is not null
connect by prior menu_id=sub_menu_id
O/P: *16*
Now if I write the query to get the number of record manually upto level 2 thats gives me the output as *36*.
select distinct(SUB_MENU_ID) from FND_MENU_ENTRIES_VL
where MENU_ID = 76580
and SUB_MENU_ID is not null
union
select distinct(SUB_MENU_ID) from FND_MENU_ENTRIES_VL where MENU_ID in(
select distinct(SUB_MENU_ID) from FND_MENU_ENTRIES_VL where MENU_ID = 76580
and SUB_MENU_ID is not null)
Please let know whats wrong with the first query.

Answer 1

Hi,
Whenever you have a question, please post CREATE TABLE and INSERT statements for your sample data, so that the people who want to help you can re-create the problem and test their ideas. From looking at your posting:
981094 wrote:
SUB_MENU_ID     MENU_ID
67723     72570
67723     72581
77139
     76580It's impossible to know even which columns are NULL.
Read the forum FAQ {message:id=9360002} again, especially the part about sample data (section 7) and the part on \ tags (section 9).
If you want to restrict a CONNECT BY query to LEVEL<x, then just include that condition in the CONNECT BY clause:SELECT COUNT (sub_menu_id)
FROM      fnd_menu_entries_vl
START WITH     menu_id          = 76580
AND     sub_menu_id     IS NOT NULL
CONNECT BY      PRIOR menu_id     = sub_menu_id
     AND     LEVEL           <= 2
You could also put that condition in a WHERE clause, to discard the rows after they were found.  But it's more efficient to put conditions like that in the CONNECT BY clause, so the unwanted rows are not found in the first place.
Your CONNECT BY query does not consider whether the sub_menu_ids found were distinct or not.  If you're trying to find an alternative query that does not use CONNECT BY, why are you including DISTINCT when that wasn't part of the original query?
In the UNION query you posted, the first branch (before the keyword UNION) corresponds to LEVEL=1 of the CONNECT BY query, but the second branch (after the keyword UNION) corresponds to what would be LEVEL=2 if the CONNECT BY condition was
"menu_id = PRIOR sub_menu_id", but for your CONNECT BY condition:
"PRIOR menu_id = sub_menu_id", a corresponding UNION query would be:SELECT sub_menu_id
FROM      fnd_menu_entries_vl
WHERE     menu_id      = 76580
AND     sub_menu_id     IS NOT NULL
UNION ALL
SELECT sub_menu_id
FROM     fnd_menu_entries_vl
WHERE     sub_menu_id IN (
          SELECT menu_id     -- DISTINCT not needed in an IN sub-query
               FROM fnd_menu_entries_vl
               WHERE menu_id     = 76580
               AND sub_menu_id     IS NOT NULL
Depending on what results you want, you may or may not need SELECT *DISTINCT* outside of the IN-subquery, but you never need DISTINCT in the IN-subquery.