Question

I have few node types and some of them have an extra field is linked to taxonomy vocabulary. How can i get taxonomy vocabulary id or name if i know field name and node type where this field there exists?

Answer 1

In Drupal 7 fields can be added to any entity/bundle, and for a term reference field the vocabularies used are set on the field level, not on the entity/bundle level.

So you don’t need to query the field settings for a particular content type, but simply the settings for the field itself. The vocabulary machine names are stored in the allowed_values key of the settings array returned from field_info_field():

$field_name = 'field_name_of_field';
$info = field_info_field($field_name);

$vocab_keys = array();
foreach ($info['settings']['allowed_values'] as $item) {
  $vocab_keys[] = $item['vocabulary'];
}

// $vocab_keys now contains an array of all vocabulary machine names allowed on this field

Hope that helps