Query and sort by field on entity referenced object

Question

I have a custom content type that has an entity reference field, that refers to an existing node from a different content type.

I'm performing the query like so

$query = \Drupal::entityQuery('node')
->condition('status', NODE_PUBLISHED)
->condition('type', 'issue');

$nids = $query->execute();

Each of these issue nodes have a field_publication field that refers to a publication node. Each of these publication nodes have a field_permission_category that I'm grabbing like so.

foreach ($nids as $nid) {
   $node = NODE::load($nid);
   $pub = $node->field_publication->entity;
   $pub_permission = $pub->field_permission_category->value;
}

But I want to be able to order the results of the initial query by the value of field_permission_category from the referenced field, but I'm not sure how to go about that, and I'm not even sure that's possible. Basically I want to be able to do

$query = \Drupal::entityQuery('node')
->condition('status', NODE_PUBLISHED)
->condition('type', 'issue')
->sort('field_publication->entity->field_permission_category->value', DESC);

Can you sort a query by a field inside a referenced node?

Answer 1

The answer by Clive is correct. I used this query for a project :

$query->sort('field_projets.entity.field_date_mise_en_prod', 'DESC');

'field_projets' is the field name of the entity reference field on my node.

And 'field_date_mise_en_prod' is the name of a date field belonging to the referenced entity .

You can also use this syntax on conditions. Exemple :

$query->condition('field_tags.entity.name', 'cats');

You asking for a tag with the name 'cats'.