Why doesn't the id column ( PRIMARY KEY, AUTO_INCREMENT ) use UNSIGNED mode?

Question

MySQL

Good afternoon. In many lessons and examples I see tables by type:

CREATE TABLE name (
  id int(11) NOT NULL AUTO_INCREMENT,
  ...
  PRIMARY KEY ( id )
) DEFAULT CHARSET=utf8;

Why don't many of the examples use an unsigned identifier? Does it threaten something? Or does it often go to the minus for many?

Answer 1

You can use it, examples are written as simply as possible, mostly so that they are easy to understand.