Entity field query example

entityfield query

$query = new EntityFieldQuery();

$query->entityCondition('entity_type', 'node')
->entityCondition('bundle', 'event')
->propertyCondition('status', 1);
$noderesult = $query->execute();
if (isset($noderesult['node'])) {
  $kb_items_nids = array_keys($noderesult['node']);
	$kb_items = entity_load('node', $kb_items_nids);
		//	dsm($kb_items);
}
foreach ($kb_items as $item) {
	$entity=$item;
	$node_wrapper = entity_metadata_wrapper('node', $entity);
	//update date field
	$node_wrapper->field_date->set(strtotime($v['date']));

	$node_wrapper->save();
}