get_metadata_by_mid() WordPress Function
The get_metadata_by_mid() function is used to retrieve metadata from a specified WordPress object. This function is useful for retrieving specific pieces of metadata from an object, rather than retrieving all metadata associated with an object.
get_metadata_by_mid( string $meta_type, int $meta_id ) #
Retrieves metadata by meta ID.
Parameters
- $meta_type
(string)(Required)Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user', or any other object type with an associated meta table.
- $meta_id
(int)(Required)ID for a specific meta row.
Return
(stdClass|false) Metadata object, or boolean false if the metadata doesn't exist.
- 'meta_key'
(string) The meta key. - 'meta_value'
(mixed) The unserialized meta value. - 'meta_id'
(string) Optional. The meta ID when the meta type is any value except 'user'. - 'umeta_id'
(string) Optional. The meta ID when the meta type is 'user'. - 'post_id'
(string) Optional. The object ID when the meta type is 'post'. - 'comment_id'
(string) Optional. The object ID when the meta type is 'comment'. - 'term_id'
(string) Optional. The object ID when the meta type is 'term'. - 'user_id'
(string) Optional. The object ID when the meta type is 'user'.
Source
File: wp-includes/meta.php
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;
}
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Changelog
| Version | Description |
|---|---|
| 3.3.0 | Introduced. |