How to load a node by a field value?

Question

I want to load a certain node. I don't know the id of the node but I do know that it has a certain hash field that is unique and I know that hash.

I want to load the node via the hash field. How can I do that?

Answer 1

You can achieve by using EntityFieldQuery.

For D8 EntityFieldQuery has been rewritten.

Drupal 8:

$query = \Drupal::entityQuery('entity_test');
$default_langcode_group = $query->andConditionGroup()
  ->condition('user_id', $properties[$default_langcode]['user_id'], '=', $default_langcode)
  ->condition('name', $properties[$default_langcode]['name'], '=', $default_langcode);
$langcode_group = $query->andConditionGroup()
  ->condition('name', $properties[$langcode]['name'], '=', $langcode)
  ->condition("$this->field_name.value", $field_value, '=', $langcode);
$result = $query
  ->condition('langcode', $default_langcode)
  ->condition($default_langcode_group)
  ->condition($langcode_group)
  ->sort('name', 'ASC', $default_langcode)
  ->execute();

How do I fetch the values of an entity's field?

$query = \Drupal::entityQuery('node')
    ->condition('status', 1)
    ->condition('changed', REQUEST_TIME, '<')
    ->condition('title', 'cat', 'CONTAINS')
    ->condition('field_tags.entity.name', 'cats');

$nids = $query->execute();

Answer 2

The quickest way to load a specific node by field value is to use the method loadByProperties().

You specify one or more field values and returned is an array containing the nodes matching the field values:

$nodes = \Drupal::entityTypeManager()
  ->getStorage('node')
  ->loadByProperties([
      'title' => $title,
      'field_hash' => 'YOUR_HASH',
    ]);

Normally you loop over the nodes. In your case you are looking for one specific node. A single node is also returned in array, so apply reset() and this returns either the node or NULL if nothing was found:

if ($node = reset($nodes)) {
  // found $node that matches the title
}

Answer 3

To load entities (nodes, users etc.) based on an array of multiple possible values/types you can use the entity query or entity type manager like that:

// Get all node IDs of multiple node types.
$query = \Drupal::entityQuery('node')
  ->condition('type', ['page', 'news'], 'IN');
$nids = $query->execute();

// Get all nodes of multiple node types.
$nodes = \Drupal::entityTypeManager()
  ->getStorage('node')
  ->loadByProperties([
    'type' => ['page', 'news'],
  ]);