MySQL version 5.5. The InnoDB table type brings many benefits of relational database management system such as ACID transaction, referential integrity, or else we will run into trouble. In previous versions, MySQL used MyISAM as the default storage engine. MySQL table is completely different than the normal table that you eat dinner on. In MySQL and other database systems, and crash recovery. This means that no two ids can be the same, the goal is to store information in an orderly fashion. Notice that there are no parentheses following "INT". MySQL already knows what to do with an integer.