Question

my data looks like this in the table:

ID     Name     Parent ID ---    ----     --------- 1      Mike     null 2      Steve    1 3      George   null 4      Jim      1 

I can’t figure out how to write a linq to sql query that will return the results with the parent rows grouped with their child rows. So for example this is the result I want:

1 Mike (no parent)    2 Steve (Parent is 1)    4 Jim (Parent is 1) 3 George (no parent) 

The way I’m doing it right now is to first grab a result set of all the parent rows. Then I loop through it and find the children for each parent and insert all this into a List<> as I loop. At the end the List<> has everything in the order I want it.

But is there a way to do this in just one linq query?

Answer 1

Assuming that you have a self-referential relationship for the table, you could do something like:

 var q = db.People            .OrderBy( p => p.ParentID == null                           ? p.Name                           : p.Parent.Name + ':' + p.ID + ':' + p.Name );