在metas表中选择几个条目的最佳方法是什么？

FYI, I'm using php and MySQL.

I was wondering what is the best way to select a few (and determined) entries in a "metas" table to link them to the principal element.

For more explanations, I have a table "users" which contains principal informations : id, email, nickname. I also have an other table, "users_metas" which contains a lot of differents informations with one entry for an information (i.e. entry1 : avatar for user1, entry2 : connection for user2, ...).

For now, when I need some specifics informations from the metas table, I'm doing it like this :

SELECT u.u_nickname, u.u_email, um1.um_value as u_avatar, um2.um_value as u_connection
FROM users as u
 LEFT JOIN users_metas as um1 ON um1.um_uid = u.u_id AND um1.um_name = "avatar"
 LEFT JOIN users_metas as um2 ON um2.um_uid = u.u_id AND um2.um_name = "connection_date"
WHERE u.u_id = :u_id

It works, and after a few "benchmarks" it's way faster than doing other SELECT queries like :

SELECT u.u_nickname, u.u_email,
  (SELECT um_value FROM users_metas WHERE um_uid = u.u_id AND um_name = "avatar") as u_avatar,
  (SELECT um_value FROM users_metas WHERE um_uid = u.u_id AND um_name = "connection_date") as u_connection
...

But I was wondering if there was a better way to do that. Of course, there is not just avatar and connection informations in the metas table, but a lot of others.

Thanks for you advices.

I'm using "metas" term to speak about diverse informations about an element