Notify Author of the post if admin deletes his post and perform some function

Question

i am working on a theme in which points are added in user meta when he does a post... it works fine but the problem is when a post is deleted by the admin then the point should be reduced and the author should get intimation . The main problem is getting the author id of the post and doing function after the post is deleted....

the code i am trying is

function deletePointFromUser($post_ID) {
global $wpdb;
$authorid = $wpdb->get_var('SELECT post_author FROM wp_posts WHERE post_id = $post_ID');
$currentPointNumber = get_usermeta($authorid, 'points');

//Delete 1 to the current Point Score
$newPointNumber = $currentPointNumber - 1;  
update_usermeta( $authorid, 'points', $newPointNumber); 
 }
add_action('deleted_post', 'deletePointFromUser');

Answer 1

Firstly, it's better to user WP functions than write your own SQL. Even though it might be a bit more expensive:

$post = get_post($post_ID);
$authorid = $post->post_author;

Secondly, it's not get_usermeta(), but get_user_meta() and the complete call should include true as the third parameter:

$currentPointNumber = get_user_meta($authorid, 'points', true);

And then it's update_user_meta(), again, and you don't need to initialize a new variable, just do:

update_user_meta($authorid, 'points', $currentPointNumber-1);