WordPress 批量删除所有文章的特色图像

/**
 * WordPress 批量删除所有文章的特色图像
 * https://www.wpdaxue.com/bulk-remove-featured-images-from-posts.html
 */
global $wpdb;
$attachments = $wpdb->get_results( "
	SELECT * 
	FROM $wpdb->postmeta 
	WHERE meta_key = '_thumbnail_id'
	" );
foreach ( $attachments as $attachment ) {
	wp_delete_attachment( $attachment->meta_value, true );
}
$wpdb->query( "
	DELETE FROM $wpdb->postmeta 
	WHERE meta_key = '_thumbnail_id'
	" );