Mysql Innodb: Autoincrement non-Primary Key

Question

Is it possible to auto-increment a non-Primary Key?

Table \"book_comments\"

book_id     medium_int
timestamp   medium_int
user_id     medium_int
vote         


        

Answer 1

As of MySQL 5.5, it seems to be possible without an index or primary key an INT field to be provided with autoincrement.