In my experience primary keys are normally self-incrementing integers. Certain databases even provide this facility when creating tables, e.g. MySQL offers the (A)uto (I)ncrement attribute for a column declared as a primary key.

Is primary key identity column?

An identity is simply an auto-increasing column. A primary key is the unique column or columns that define the row. These two are often used together, but there’s no requirement that this be so.

Does MySQL primary key auto increment?

In order to avoid such complexity and to ensure that the primary key is always unique, we can use MySQL’s Auto increment feature to generate primary keys. Auto increment is used with the INT data type. The INT data type supports both signed and unsigned values.