如何在LINQ to SQL查询中排除特定的关联记录？

Question

Assume I have the following data:

Parent
  > Child 1 (Alive = true)
  > Child 2 (Alive = true)
    > Grandchild 1 (Alive = false)
    > Grandchild 2 (Alive = true)
  > Child 3 (Alive = false)
    > Grandchild 3 (Alive = false)

And I want to write a query to select all the records where Alive is true, thereby excluding anything where Alive is false. This is the syntax I'm trying to figure out:

from p
in this.People
where p.IsAlive && (p.Children.IsAlive)  && (p.Children.Children.IsAlive)
select p

I would like the result set to look like this:

Parent
  > Child 1 (Alive = true)
  > Child 2 (Alive = true)
    > Grandchild 2 (Alive = true)

Answer 1

You can do like below way: 1) Create table People with recursive relationship by ParentID column:

Table name : People
ID  Name        ParentID IsAlive
1   Parent1     Null       1
2   Child1      1          1
3   Child2      1          1
4   GrandChild1 3          1
5   GrandChild2 3          0
6   Child3      1          0
7   GrandChild3 6          0

2) Execute query like below for Alive records:

from p
in this.People
where p.IsAlive 
select p

Please let me know , is this way works for you ?