How do I load entities with Null values?

Question

The following fails with an exception.

\Drupal::entityTypeManager()->getStorage('foo_module_division')->loadByProperties(['enabled'=>TRUE, 'parent_code'=> NULL]).

How else do I specify I want to load entities whose parent_code field is NULL?

Answer 1

The exception is the result of how EntityStorageBase::loadByProperties() builds the underlying WHERE clause; it's utilizing ::buildPropertyQuery() which casts NULL to an array then uses the IN operator to compare; this won't work since you need a IS NULL query to find NULL entries in the DB.

Instead, you can build your own entity storage query in a similar way as loadByProperties():

$es = \Drupal::entityTypeManager()->getStorage('foo_module_division')
$q = $es->getQuery();
$results = $q->condition('parent_code', NULL, 'IS')->condition('enabled', TRUE)->execute();
return $results ? $es->loadMultiple($results) : array();

Answer 2

The example of getting articles that has empty body:

  $entityStorage = \Drupal::entityTypeManager()->getStorage('node');
  $query = $entityStorage->getQuery();
  $query->condition('type', 'article');
  $query->notExists('body');
  $nids = $query->execute();
  $nodes = $entityStorage->loadMultiple($nids);