MySQL替代二进制自动增量列？

Question

MySQL has auto_increment which allows us to create unique primary keys automatically.

However, this only works for integer columns. There doesn't seem to be a way to combine auto_increment with binary columns, for example:

mysql > create table Users(Id binary(6) auto_increment, primary key(id));

#1063 - Incorrect column specifier for column 'Id'

How can we create or implement an auto-increment binary column?

(Finding a solution which maintains atomicity and have comparable performance to auto_increment integer columns.)

Answer 1

A trigger that is called before each insert operation should be safe for transactions and will accomplish what you want.

Checkout the manual page on triggers.