Get a taxonomy id(tid) from a node id (nid)

Question

  if($node->type=='student')
    {
        $nid = $node->nid;
        print_r("The node id is: ".$nid.'<br/>');
        $tid =db_query('SELECT tid FROM {taxonomy_index} WHERE nid = :nid', 
                  array(':nid' => $nid)
                )->fetchField();
        print_r('The tid is: '.$tid);exit(0);
    }

I tried but nothing is displayed...I just want to get the tid.

Answer 1

May be you can use field_get_items: It will return return the field items in the language they currently would be displayed.

// Pass the node object $node instead of $nid.
// Get the field name of taxonomy field from content type.
$term_id = field_get_items('node', $node, $field_name);

$term_id will be array containing the term ids.

Answer 2

As commented by Neok, you can get the term id mapped with your node directly from node object like

$node->field_example['und'][0]['tid'];

Answer 3

    <?php 
        $activities_name = "activities"; // suppose you created a vocabulary that is "activities" which is attach with a particular node.

//NOw I will fetch all the details for this vocabulary from database

        $activities_result = taxonomy_vocabulary_machine_name_load($activities_name);

        echo $activities_result->vid; // now print the attached vocabulary id 

now fetch all the terms id tose are associated with this vocabulary

        $activities_term_data = taxonomy_get_tree($activities_result->vid, $parent = 0, $max_depth = NULL, $load_entities = FALSE);

        foreach($activities_term_data as $k => $v)
        {
        echo $v->tid."=>".$v->name; // print the termid and term name.
        }

    //$v->tid will show the terms ids.

// by the help of code you can get the vocabulary id and associated terms ids ( actually its not clear to me what the user exactly want term id or vocabulary id)
         ?>

Answer 4

Instead of using db_query simply use db_select as

$tid = db_select('taxonomy_index', 'taxonomy_index')
  ->fields('taxonomy_index', array('tid', 'tid'))
  ->condition('nid', $nid)
  ->execute()->fetchAllKeyed();

So executing this would generate an array containing the list of tags a content is tagged with.

Thanks,