recursive query Sort - sql

Question

I have a Standard table, which sotres parent, child category relationship...like this.
id, parent, catName, sort
And I use the following query to create a recursive tree
;WITH cte AS (
SELECT 0 AS lvl, id, catName, parent,levels,sort,
CAST(id AS VARCHAR(128)) AS path
FROM CategoriesMap WHERE parent =0
UNION ALL
SELECT p.lvl + 1, c.id, c.catName, c.parent,c.levels,c.sort,
CAST(p.path + '_' + CAST(c.id AS VARCHAR) AS VARCHAR(128))
FROM CategoriesMap c
INNER JOIN cte p ON p.id = c.parent
)
SELECT
id,
catName AS catName,
lvl,
levels,
path,
parent,
sort
FROM cte
ORDER BY path
And the output is like this Image:
Look for the Row with value ASP.NET & CLASSIC ASP, these are the last leaf(children) for the technology > Software (parents), I want to sort the LAST CHILDREN of any given parent (last parent). I can have multiple parents for a given node (last child) & all I care about is sort the LAST Children (leaf) using the "Sort" column.
so basicly "Classic Asp" shoud be before "Asp.Net" (Last Column is SORT column in my image).
My query is fine, it returns the results as expected...only challenege is i want to SORT the last NODE using the SORT column in table, last node can have 3 or 4 children which I want to sort, all nodes above the last node are its parents (which are in correct order already).
I want output like this.... Internet > ISP's > CableVision (1) :
Verizon (2) as you can see CableVision & Verizon have Sort Value of 1
& then 2, Now lets say we have Shopping > Coupons > Macys(0) : Sears
(2), same thing....I want Macys & Sears to be sorted...and its pretty
obvious their parents are Shopping > Coupons.
#Richard aka cyberkiwi, after applying your code, my sorting for Categories table is very random. output is below

Answer 1

Delaying the calculation of the path for one level, so the final result set has the parent path (ppath) available:
;WITH cte AS (
SELECT 0 AS lvl, id, catName, parent,levels,sort,
CAST('' AS VARCHAR(128)) AS ppath
FROM CategoriesMap WHERE parent =0
UNION ALL
SELECT p.lvl + 1, c.id, c.catName, c.parent,c.levels,c.sort,
CAST(p.ppath + '_' + CAST(p.id AS VARCHAR) AS VARCHAR(128))
FROM CategoriesMap c
INNER JOIN cte p ON p.id = c.parent
)
SELECT
id,
catName,
lvl,
levels,
CAST(ppath + '_' + CAST(id AS VARCHAR) AS VARCHAR(128)) AS path,
parent,
sort
FROM cte
ORDER BY
CASE WHEN sort IS NULL
THEN path
ELSE ppath
END
, sort ;
Not really sure why the above gives error. This will not:
ORDER BY
CASE WHEN sort IS NULL
THEN CAST(ppath + '_' + CAST(id AS VARCHAR) AS VARCHAR(128))
ELSE ppath
END
, sort ;

Answer 2

This SQL Fiddle should give you what you need.
The trick really is when you mix leaves with branches. In my solution, leaves ALWAYS appear before branches, and within the leaves (even when inter-mixed with branches), they are sorted by the sort column of course.
DDL
create table CategoriesMap(
id int, parent int, catname varchar(20), sort int);
insert CategoriesMap select
1, 0, 'Activities', null union all select
2, 0, 'Property', null union all select
3, 2, 'For rent', null union all select
4, 2, 'For sale', null union all select
12, 0, 'Technology', 3 union all select
15, 12, 'Hardware', null union all select
21, 12, 'Phones', null union all select
22, 15, 'Computers', null union all select
18, 12, 'Software', null union all select
19, 18, 'Asp.net', 2 union all select
20, 18, 'SQL', 3 union all select
23, 18, 'Php', 4 union all select
24, 18, 'Classic ASP', 1;
Query
;WITH leaves AS (
SELECT A.id
FROM CategoriesMap A
LEFT JOIN CategoriesMap B ON A.id=B.parent
WHERE B.id is null
)
,cte AS (
SELECT 0 AS lvl, id, catName, parent,sort,
CAST(id AS VARCHAR(MAX)) AS path,
'/'+CAST(id AS VARCHAR(MAX))+'/' AS hier
FROM CategoriesMap
WHERE parent =0
UNION ALL
SELECT p.lvl + 1, c.id, c.catName, c.parent,c.sort,
p.path + '_' + CAST(c.id AS VARCHAR(MAX)),
p.hier + CAST(c.id AS VARCHAR(MAX)) + '/'
FROM CategoriesMap c
JOIN cte p ON p.id = c.parent
)
SELECT c.id,
c.catName,
c.lvl,
--levels,
c.path,
--c.hier,
c.parent,
c.sort
FROM cte c
LEFT JOIN leaves l on l.id=c.id
ORDER BY CASE WHEN l.id is null
then cast(hier as hierarchyid)
else cast(hier as hierarchyid).GetAncestor(1)
END,
CASE WHEN l.id is null then 0 else 1 end,
sort