How to return both parent and child using LINQ against 1 table

Question

Been looking for a solution for this but haven\'t been able to find one so far.

I\'m fairly sure its possible with one linq call but having trouble working it out.

Answer 1

I was going to use a GroupJoin, but this should satisfy your requirement.

 var query = dataContext.YourTable.Where(x => x.ValidFlag == 1 &&
 (x.ParentId == null ||
    dataContext.YourTable.Where( y => y.ParentId == x.Id)
    .First().ValidFlag == 1))
 .ToList();
                      .