Question

Hierarchical Structures Database Select By Lambda Expression
Hi My Table Structure is recursive

ID

ParentID

UserGROUPNAME

How Can I select Subset an Id from my contex By Lambda Expression like this

I Try to select first

var keys = db.UsersGroups.Select(x => x).Where(u => u.GroupMasterID == 1).ToArray();

var UsersGroup = db.UsersGroups.Where(x => keys.Contains(x.GroupMasterID));

But I think it’s return wrong or return just 2 level data

Please Help me

Answer 1

finally I create a sql function

like this

Create  FUNCTION [dbo].[GET_USERGROUPLIST]
(
    @GROUPID INT
)
RETURNS  TABLE 
AS
RETURN 
(
    WITH UsersGroups_CTE AS (
SELECT *
FROM [dbo].[UsersGroups]
WHERE ID = @GROUPID
UNION ALL
SELECT e.ID, e.GroupName, e.ParentID ,e.Status
FROM [dbo].[UsersGroups] e
INNER JOIN UsersGroups_CTE ucte ON ucte.ID = e.ParentID
)
SELECT *
FROM UsersGroups_CTE Where UsersGroups_CTE.Status = 1
); 

and Next Use in my model like this

db.GET_USERGROUPLIST(1);

Many Thanks to lontivero for him suggestion