SSRS not showing all rows by level (hierarchy) - sql

Question

Ok folks, this is driving me crazy...
I have a report that pulls back details for a number of features. THese features can hang off others, exist in their own right or both.
I have the following data as the result of the query:
Feature_ID Parent_ID
24
24 25
20
26 12
12
21 23
26 20
22
24 23
23 26
24 27
27 28
24 22
29 20
23
25
27 29
22 26
28 12
As you can see, some of the features fit in multiple places in the hierarchy. However, all I get back in the report is:
I am grouping on Feature_ID, recursive parent is Parent_ID. What am I missing?

Answer 1

By your wording and unexpected output it feels like you are looking for a list of distinct levels and features. Hopefully the following is helpful. If not, perhaps you can provide some additional context to understand what you are looking for.
declare #table table (Feature_ID int, Parent_ID int);
insert #table values
(24,null),
(24,25),
(20,null),
(26,12),
(12,null),
(21,23),
(26,20),
(22,null),
(24,23),
(23,26),
(24,27),
(27,28),
(24,22),
(29,20),
(23,null),
(25,null),
(27,29),
(22,26),
(28,12);
select * from #table order by 1,2;
select * from #table order by 2,1;
with cte as (
select Feature_ID, Parent_ID, 0 [Level], CAST(Feature_ID as varchar(200)) [Path]
from #table
where Parent_ID is null
union all
select t.Feature_ID, t.Parent_ID, c.[Level] + 1, cast(c.[Path] + '|' + CAST(t.Feature_ID as varchar(200)) as varchar(200))
from #table t
join cte c
on c.Feature_ID = t.Parent_ID
)
select distinct [Level], Feature_ID
from cte
order by [Level], Feature_ID;
This gives the following result:
Level Feature_ID
0 12
0 20
0 22
0 23
0 24
0 25
1 21
1 24
1 26
1 28
1 29
2 22
2 23
2 27
3 21
3 24