WordPress Version: 5.9
/**
* Retrieves metadata by meta ID.
*
* @since 3.3.0
*
* @global wpdb $wpdb WordPress database abstraction object.
*
* @param string $meta_type Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user',
* or any other object type with an associated meta table.
* @param int $meta_id ID for a specific meta row.
* @return stdClass|false {
* Metadata object, or boolean `false` if the metadata doesn't exist.
*
* @type string $meta_key The meta key.
* @type mixed $meta_value The unserialized meta value.
* @type string $meta_id Optional. The meta ID when the meta type is any value except 'user'.
* @type string $umeta_id Optional. The meta ID when the meta type is 'user'.
* @type string $post_id Optional. The object ID when the meta type is 'post'.
* @type string $comment_id Optional. The object ID when the meta type is 'comment'.
* @type string $term_id Optional. The object ID when the meta type is 'term'.
* @type string $user_id Optional. The object ID when the meta type is 'user'.
* }
*/
function get_metadata_by_mid($meta_type, $meta_id)
{
global $wpdb;
if (!$meta_type || !is_numeric($meta_id) || floor($meta_id) != $meta_id) {
return false;
}
$meta_id = (int) $meta_id;
if ($meta_id <= 0) {
return false;
}
$table = _get_meta_table($meta_type);
if (!$table) {
return false;
}
/**
* Short-circuits the return value when fetching a meta field by meta ID.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
* Returning a non-null value will effectively short-circuit the function.
*
* Possible hook names include:
*
* - `get_post_metadata_by_mid`
* - `get_comment_metadata_by_mid`
* - `get_term_metadata_by_mid`
* - `get_user_metadata_by_mid`
*
* @since 5.0.0
*
* @param stdClass|null $value The value to return.
* @param int $meta_id Meta ID.
*/
$check = apply_filters("get_{$meta_type}_metadata_by_mid", null, $meta_id);
if (null !== $check) {
return $check;
}
$id_column = ('user' === $meta_type) ? 'umeta_id' : 'meta_id';
$meta = $wpdb->get_row($wpdb->prepare("SELECT * FROM {$table} WHERE {$id_column} = %d", $meta_id));
if (empty($meta)) {
return false;
}
if (isset($meta->meta_value)) {
$meta->meta_value = maybe_unserialize($meta->meta_value);
}
return $meta;
}