Email Attachment

[TalkNet_TechnoS]

I have 3 Tables:
Products (It has 1pdf or image of each product)
Orders (Parent)
Items of the Order (Child)

I have a Workflow that sends the Order with the Items Detail
and I need to attach the pdf that correspond to the Items. or other attachments.
What I can not achieve is to relate the 3 tables in the expression “Other Attachment file name”

SELECT (Products [PDF], CONTAINS (Items, [_ THISROW]. [Order Id]))

I understand that I would have to be able to extract from the Table of Items, the Id Products that correspond to the Order Id.

But I do not realize how to do it!

Some help?

From already thank you very much!