drupal/core/modules/taxonomy/taxonomy.install

<?php

/**
 * @file
 * Install, update and uninstall functions for the taxonomy module.
 */

/**
 * Implements hook_schema().
 */
function taxonomy_schema() {
  $schema['taxonomy_term_data'] = array(
    'description' => 'Stores term information.',
    'fields' => array(
      'tid' => array(
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'description' => 'Primary Key: Unique term ID.',
      ),
      'uuid' => array(
        'description' => 'Unique Key: Universally unique identifier for this entity.',
        'type' => 'varchar',
        'length' => 128,
        'not null' => FALSE,
      ),
      'vid' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
        'description' => 'The ID of the vocabulary to which the term is assigned.',
      ),
      'langcode' => array(
        'description' => 'The {language}.langcode of this term.',
        'type' => 'varchar',
        'length' => 12,
        'not null' => TRUE,
        'default' => '',
      ),
      'name' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'default' => '',
        'description' => 'The term name.',
      ),
      'description__value' => array(
        'type' => 'text',
        'not null' => FALSE,
        'size' => 'big',
        'description' => 'A description of the term.',
      ),
      'description__format' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => FALSE,
        'description' => 'The filter format ID of the description.',
      ),
      'weight' => array(
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
        'description' => 'The weight of this term in relation to other terms.',
      ),
      'changed' => array(
        'description' => 'The Unix timestamp when the term was most recently saved.',
        'type' => 'int',
        'not null' => TRUE,
        'default' => 0,
      ),
    ),
    'primary key' => array('tid'),
    'unique keys' => array(
      'uuid' => array('uuid'),
    ),
    'indexes' => array(
      'taxonomy_tree' => array(array('vid', 64), 'weight', 'name'),
      'vid_name' => array(array('vid', 64), 'name'),
      'name' => array('name'),
    ),
  );

  $schema['taxonomy_term_hierarchy'] = array(
    'description' => 'Stores the hierarchical relationship between terms.',
    'fields' => array(
      'tid' => array(
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
        'description' => 'Primary Key: The {taxonomy_term_data}.tid of the term.',
      ),
      'parent' => array(
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
        'description' => "Primary Key: The {taxonomy_term_data}.tid of the term's parent. 0 indicates no parent.",
      ),
    ),
    'indexes' => array(
      'parent' => array('parent'),
    ),
    'foreign keys' => array(
      'taxonomy_term_data' => array(
        'table' => 'taxonomy_term_data',
        'columns' => array('tid' => 'tid'),
      ),
    ),
    'primary key' => array('tid', 'parent'),
  );

  $schema['taxonomy_index'] = array(
    'description' => 'Maintains denormalized information about node/term relationships.',
    'fields' => array(
      'nid' => array(
        'description' => 'The {node}.nid this record tracks.',
        'type' => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'default' => 0,
      ),
      'tid' => array(
         'description' => 'The term ID.',
         'type' => 'int',
         'unsigned' => TRUE,
         'not null' => TRUE,
         'default' => 0,
      ),
      'sticky' => array(
        'description' => 'Boolean indicating whether the node is sticky.',
        'type' => 'int',
        'not null' => FALSE,
        'default' => 0,
        'size' => 'tiny',
      ),
      'created' => array(
        'description' => 'The Unix timestamp when the node was created.',
        'type' => 'int',
        'not null' => TRUE,
        'default'=> 0,
      ),
    ),
    'indexes' => array(
      'term_node' => array('tid', 'sticky', 'created'),
      'nid' => array('nid'),
    ),
    'foreign keys' => array(
      'tracked_node' => array(
        'table' => 'node',
        'columns' => array('nid' => 'nid'),
      ),
      'term' => array(
        'table' => 'taxonomy_term_data',
        'columns' => array('tid' => 'tid'),
      ),
    ),
  );

  return $schema;
}