How can I eliminate duplicate Drupal nodes in a View when one CT references the other?

Question

Drupal 7 with relevant Modules: Views & Entity Reference

I have a view that simply shows the "Teaser" display type of two different Content Type records, we'll say they are Article and Page. This is built into a Views Page.

My Article CT has some simple fields that are shown.

My Page CT has a few fields, but also an Entity Reference field (unlimited entries). The Entity Reference field points to other Article nodes.

My View then, as expected, shows each record's Teaser display and of course when a Page record references another Article record, that Article's teaser is shown as part of the Page teaser.

This is great. The problem is, I do not want to show duplicate Article teasers. That means, if a Page references an Article, I don't want to show that same Article teaser as an individual listing.

Think of it like this, I have these Articles:

1. Article 1
2. Article 2
3. Article 3

And I have these Pages:

1. Page 4
2. Page 5
3. Page 6

Page 4 points -> at Article 1 and Article 2

Page 6 points -> at Article 2

TL;DR

Right now the view would show something like:

• Article 1
• Article 2
• Page 4
  • Article 1
  • Article 2
• Page 5
• Page 6
  • Article 2
• Article 3

What I want is this:

• Page 4
  • Article 1
  • Article 2
• Page 5
• Page 6
  • Article 2
• Article 3

Here's a Diagram: https://i.stack.imgur.com/2joEr.jpg

Answer 1

My guess would be to use fields instead of teasers, first. Then, use filter to undisplay Articles that are nodereferenced by pages - you then would only have pages and unreferenced articles showing up.

You might be able to do that with the relationship entityreference - reverse, or with views PhP if it doesn't work.

Answer 2

• Go and edit your view
• In Advanced » OTHER section by enabling Use aggregation: Yes
• In FIELDS or FILTER CRITERIA section, select and apply Aggregation settings for which fields you want to group by or distinct.

Answer 3

I ended up knocking this out by making use of the Corresponding Entity Reference module (CER). This creates a 2-way relationship that is sync'd between the parent<->child. Using that, I could simply filter all children which have a parent from the View.