Beginners' guide to stored procedures with MySQL?

Question

I\'ve Googled but come up with nothing that I can get my head around.

Are the performance gains from using stored procedures significant?

Would I still want

Answer 1

I have created one procedure but the time of call this procedure what parameter I can pass to get the output

CREATE DEFINER=`root`@`localhost` PROCEDURE `A`(

In user_id bigint,
Out address varchar(250)

)
BEGIN

select Address into address
from UserDetail_table
where User_ID = user_id; 

END