Guest Author backfill

gistfile1.txt

$guest_posts = get_posts(
	array(
		'post_status' => 'publish',
		'posts_per_page' => -1,
		'meta_key' => 'time_guest_author',
		'meta_value' => 0,
		'meta_compare' => '>=',
	)
);

if( $guest_posts ) {
	
	$non_guest_posts = get_posts(
		array(
			'post_status' => 'publish',
			'posts_per_page' => -1,
			'posts__not_in' = wp_list_pluck( $guest_posts, 'ID' );
		)
	);
	
	if( $non_guest_posts ) {
		foreach( $non_guest_posts as $post ) {
			update_post_meta( $post->ID, 'time_guest_author', 0 );
		}
	}
}