Getting Taxonomy Terms Names in Drupal 7

Source code viewer
$terms = db_query('SELECT name FROM taxonomy_term_data');
foreach ($terms as $term) {
  echo $term->name;
}
Programming Language: PHP

Get Taxonomy Terms Names Of Certain Parent:

This query gets all taxonomy terms names of certain parent. In this case it gets all the main terms. You can make a recursive function and make a treeview of categorie names. Tutorial that shows how to make recursive funtion: Tutorial: Create Treeview Using Recursion in PHP.

Source code viewer
$terms = db_query('SELECT taxonomy_term_data.name AS name, taxonomy_term_data.tid AS tid FROM taxonomy_term_data, taxonomy_term_hierarchy WHERE taxonomy_term_data.tid = taxonomy_term_hierarchy.tid AND taxonomy_term_hierarchy.parent = 0');
foreach ($terms as $term) {
  echo $term->name;
}
Programming Language: PHP