Auto Incrementing

Hi! Is it important to check the box AI when declaring a column as PK? Will it not auto-increment as a default if the box is not checked? Thank you.

Even-though it is common, you need to specify anything such as AI if you want this behaviour.
A PK is just a contraint identifying an entry. So there are unique constraint implied.
You could have the software manage those IDs instead. Then you do not want AI and so you are given the ability to do as you wish.

Thanks for the insight.