list or get meta_key where meta_value is 'something'

Question

I'm trying to get with

get_user_meta

the meta_key where the meta_value is 'ive-read-this'

But I do not get the value. What should I do?

Answer 1

I agree with @Simon Blackbourn, but for arguments sake, here's one technique:

$data = get_user_meta( $user_id );
$data = wp_list_filter( $data, array( 'ive-read-this' ) );
$keys = array_keys( $data );

Answer 2

Bearing in mind I haven't seen the rest of your code or know the context of your question, I would suggest that you're doing it wrong: you should always know the name of a usermeta that you're trying to retrieve.

If you're trying to determine if a post has been read by a user, you could save the user ID as a postmeta, maybe that's a better solution?