Get post and its children with WP_Query

Question

I want the parent post and its children posts. I don't know the parent post ID, only that its post_password field is not empty.

It's very similar to this question except the post ID is not known in my case.

Answer 1

The question that is similar to your question, i took sample code from there. you can replace 'post_parent with this.

global $post;
$args = [
    'wpse_include_parent' => true,
    'post_parent'         => wp_get_post_parent_id( $post->ID ),
    'post_type'           => 'post'
    // Add additional arguments
];
$q = new WP_Query( $args );

This code will get the parents post id when you are inside children post