Merge meta_value's into a single row and then loop

Question

I have a query where I want to merge values from the wp_users and wp_meta tables, including the meta values of a given meta key. This key could have multiple entries.

SELECT
    u.id,
    (select meta_value from wp_usermeta where user_id = u.id and meta_key = 'first_name' limit 1) as first_name,
    (select meta_value from wp_usermeta where user_id = u.id and meta_key = 'last_name' limit 1) as last_name,
    u.user_email AS email,
    u.user_registered AS registered,
    (select meta_value from wp_usermeta where user_id = u.id and meta_key = '_example_key') as my_custom_meta_values
FROM wp_users u

This query returns a single column (my_custom_meta_values), containing all the serialised values from wp_usermeta for the given key.

My question is, how do I then loop over these values in PHP? I'm assuming that simply deserialising the row will fail.

Answer 1

It would appear simply un-serialising works:

        $results =  $wpdb->get_results( $sql_str );

        foreach($results as &$result) {

            $result-> my_custom_meta_values = unserialize($result-> my_custom_meta_values);
        }

If anyone can suggest a more efficient way to do this, I'd be interested.