asp.net mvc c# changing slug in child records - sql

Question

i have these records coming from my stored procedure which i am calling in linq to sql
int_PostTypeId vcr_PostType int_PostTypeId_fk vcr_Slug HLevel
49 c 36 c 1
77 e 49 c/e 2
78 f 77 c/e/f 3
79 g 77 c/e/g 3
i have these set of records.
suppose while editing the int_PostTypeId 49 i changed the slug to c1
1) now the slug in the child records also ought to be changed.
slug in 77 will become c1/e
slug in 78 will become c1/e/f
slug in 79 will become c1/e/g
2) if i edit the record 77 and change the slug to c/e2 then the slug 78 and 79 should also be changed to c/e2/f and c/e2/g.
so editing the slug in the record will change the child slug if exists. what is the most appropriate and efficient way of doing it in linq. i am taking the recursive loop path but i think that is highly inefficient. any idea for more general approach? or any other approach.

Answer 1

If I'm understanding you correctly, you're actually updating a column called vcr_Slug in a record somewhere, rather than building the column's value in your stored procedure. Since you're actually using a stored procedure, why not calculate the column's value? I'm not sure if you're using a recursive common table expression to select your results, but if you are, it could take the form of something like the following (making some assumptions about your table structure which may not, of course, be completely representative):
CREATE FUNCTION dbo.GetPostTypes(#ParentTypeID int)
RETURNS TABLE
AS RETURN
(
WITH CurrentPostTypes(int_PostTypeId, vcr_PostType, int_PostTypeId_fk, vcr_Slug,
HLevel)
AS
(
-- Anchor member definition
SELECT pt.int_PostTypeId, pt.vcr_PostType, pt.int_PostTypeId_fk,
pt.vcr_Slug, 1 AS HLevel
FROM dbo.tblPostTypes AS pt
WHERE pt.int_PostTypeId = #ParentTypeID
UNION ALL
-- Recursive member definition
SELECT pt.int_PostTypeId, pt.vcr_PostType, pt.int_PostTypeId_fk,
cpt.vcr_Slug + '/' + pt.vcr_Slug AS vcr_Slug, cpt.HLevel + 1 AS HLevel
FROM dbo.tblPostTypes AS pt
INNER JOIN CurrentPostTypes AS cpt
ON pt.int_PostTypeId_fk = cpt.int_PostTypeId
)
SELECT *
FROM CurrentPostTypes
)
You'll notice in the recursive member definition where the previous value of vcr_Slug is suffixed with a slash and the current record's column value: cpt.vcr_Slug + '/' + pt.vcr_Slug AS vcr_Slug