How to navigate through a list by foreign key in Linq-to-SQL

Question

I have these four tables SI_FILTROSRELATORIO_[something] in which one column is ID_FILTROSRELATORIO which is a foreign key to a SI_FILTROSRELATORIO table. I wanted to do something like:

var myList = db.SI_FILTROSRELATORIOs
               .Single([some query])
               .SI_FILTROSRELATORIO_[something]s

I know this is possible because I have another 2 tables which I can do this. I'm trying to replicate the effect but I don't know if I'm missing some detail because the SI_FILTROSRELATORIO_[something]'s property doesn't show up in a SI_FILTROSRELATORIO's entry, and I can't figure why.

The relationship is actually like this:

Answer 1

The problem was that the SI_FILTROSRELATORIO_[something] had no Primary Key column. The direction of the relationship also was inverted.