按元ID删除元数据
原型
delete_metadata_by_mid( string $meta_type, int $meta_id )
参数
$meta_type
(string)
(Required)
对象元数据的类型用于(例如,评论,帖子,术语或用户)。
$meta_id
(int)
(Required)
特定元行的ID
返回值
(bool)
成功删除时为True,失败时为false。
源文件
路径:wp-includes/meta.php
<?php
...
function delete_metadata_by_mid( $meta_type, $meta_id ) {
global $wpdb;
// Make sure everything is valid.
if ( ! $meta_type || ! is_numeric( $meta_id ) || floor( $meta_id ) != $meta_id ) {
return false;
}
$meta_id = intval( $meta_id );
if ( $meta_id <= 0 ) {
return false;
}
$table = _get_meta_table( $meta_type );
if ( ! $table ) {
return false;
}
// object and id columns
$column = sanitize_key($meta_type . '_id');
$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
/**
* Filters whether to delete metadata of a specific type by meta ID.
*
* The dynamic portion of the hook, `$meta_type`, refers to the meta
* object type (comment, post, term, or user). Returning a non-null value
* will effectively short-circuit the function.
*
* @since 5.0.0
*
* @param null|bool $delete Whether to allow metadata deletion of the given type.
* @param int $meta_id Meta ID.
*/
$check = apply_filters( "delete_{$meta_type}_metadata_by_mid", null, $meta_id );
if ( null !== $check ) {
return (bool) $check;
}
// Fetch the meta and go on if it's found.
if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
$object_id = $meta->{$column};
/** This action is documented in wp-includes/meta.php */
do_action( "delete_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
// Old-style action.
if ( 'post' == $meta_type || 'comment' == $meta_type ) {
/**
* Fires immediately before deleting post or comment metadata of a specific type.
*
* The dynamic portion of the hook, `$meta_type`, refers to the meta
* object type (post or comment).
*
* @since 3.4.0
*
* @param int $meta_id ID of the metadata entry to delete.
*/
do_action( "delete_{$meta_type}meta", $meta_id );
}
// Run the query, will return true if deleted, false otherwise
$result = (bool) $wpdb->delete( $table, array( $id_column => $meta_id ) );
// Clear the caches.
wp_cache_delete($object_id, $meta_type . '_meta');
/** This action is documented in wp-includes/meta.php */
do_action( "deleted_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
// Old-style action.
if ( 'post' == $meta_type || 'comment' == $meta_type ) {
/**
* Fires immediately after deleting post or comment metadata of a specific type.
*
* The dynamic portion of the hook, `$meta_type`, refers to the meta
* object type (post or comment).
*
* @since 3.4.0
*
* @param int $meta_ids Deleted metadata entry ID.
*/
do_action( "deleted_{$meta_type}meta", $meta_id );
}
return $result;
}
// Meta id was not found.
return false;
}
...
?>
其他
英文文档:https://developer.wordpress.org/reference/functions/delete_metadata_by_mid/