Reverse entity reference lookup

Question

I have a data structure where content type research has an entity reference field scientists.

The content type scientists does not have any research reference entity field though.

I can get all scientists that a particular research has through research.

But is there a way to get all researches one particular scientist has? When content types were created I wasn't involved, so I'm trying to see my options whether I can somehow click a checkbox to make this applicable.

When I tried to set up a field with type of entity reference and pointed it to research for scientists, they were empty.

Any help is highly appreciated.

Answer 1

Is there a way to get all researches one particular scientist has?

Yes, search for the scientist target id:

$nodes = \Drupal::entityTypeManager()->getStorage('node')->loadByProperties([
  'type' => 'research',
  'field_scientists' => $scientist_id,
]);