How to manipulate, create, update and delete WordPress Terms with PHP

Terms can be created, queried and edited via PHP. WordPress provides functions for this purpose.

Query a WordPress term with PHP #

To retrieve a term you can use the function get_term($term_id, $taxonomy). For this you only need the ID and the taxonomy.

$term_id = 10;
$taxonomy = "post_tag";

/**
 * @var \WP_Term $Term
 */
$Term = get_term($term_id, $taxonomy);

Query a WordPress term by slug, name or term ID #

Via get_term_by($field, $value, $taxonomy, $output = OBJECT, $filter = ‘raw’) you can also query a term by its slug, name or ID.

/**
 * Query WordPress Term with the Slug
 * @var \WP_Term|array|false $Term
 */
$Term = get_term_by("slug", "i-am-a-slug", "post_tag");

/**
 * Query WordPress Term with the Name
 * @var \WP_Term|array|false $Term
 */
$Term = get_term_by("name", "i am a name", "post_tag");

/**
 * Query WordPress Term with the Term ID
 * @var \WP_Term|array|false $Term
 */
$Term = get_term_by("term_id", 10, "post_tag");

Query all WordPress terms from one taxonomy #

Using get_terms($args) you can query all terms of a taxonomy.

$args = array(
   'taxonomy' => 'post_tag',
   'hide_empty' => false
);

/**
 * @var array<\WP_Term> $Terms
 */
$Terms = get_terms($args);

Inserting a new WordPress term at a taxonomy #

New terms can be added via wp_insert_term($term, $taxonomy, $args = array()). If the term already exists, it will be updated.

/**
 * Arguments can be specified optionally
 */
$args = array(
   'description' => 'Description',
   'parent' => 0,
   'slug' => ''
);

/**
 * Create new term in the taxonomy post_tag
 */
$term_id = wp_insert_term('I am a new term', 'post_tag', $args);

Delete a term on WordPress via PHP #

Terms can also be removed quickly and easily via PHP. For this purpose, the function wp_delete_term($term_id,$taxonomy) exists.

/**
 * Deletes the term with term ID 10 in the taxonomy post_tag
 */
$result = wp_delete_term(10, 'post_tag');

Query meta data of a term #

Like posts, terms can also contain metadata. These can be retrieved via get_term_meta($term_id, $meta_key, $single).

/**
 * Returns a single value
 * @var string|int|mixed $my_meta_data
 */
$my_meta_data = get_term_meta(10,'my_meta_data', true);

/**
 * Returns an array
 * @var array $meine_meta_daten
 */
$my_meta_data = get_term_meta(10,'my_meta_data');

Deleting metadata of a term in WordPress #

Metadata of terms can be deleted in WordPress via delete_term_meta($term_id, $meta_key, $meta_value = ”).

$result = delete_term_meta(10, 'my_meta_data');

Update/create metadata of a term via PHP #

To update already existing metadata of a term the function update_term_meta($term_id, $meta_key, $meta_value, $prev_value = ”) is used. If the data does not exist yet, it will be created.

$result = update_term_meta(10, 'my_meta_data', 'this will be outputed');