I have a request to get postmeta records with a specific meta_value.

global $wpdb;
$result = $wpdb->get_results ( " SELECT * FROM  $wpdb->postmeta WHERE $wpdb->postmeta.meta_key LIKE 'wpcomplete' " );
foreach ( $result as $page ) {
 echo maybe_unserialize($page->meta_value).'<br/>';
} 

result :

{“buttons”:{“3″:”1951965-debutant”,”4″:”1951965-intermediaire”,”5″:”1951965-expert”},”course”:”examen”}

I just need to clean the result like that

buttons :

1951965-debutant

1951965-intermediaire

1951965-expert

course :

examen