is it necessary to specify not null on a column you are defining as the primary key? Seems like that was included in the definition of pk

Answer 1

Primary key can not be null. For example. ID is a great primary key. Every entry MUST have an entry and cannot be null.

Answer 2

By default Primary key will be NOT NULL and you will not be alter the column to NULl

Answer 3

Yes. For Primary Key by default it's checking NOT NULL and UNIQUE conditions.

Answer 4

primary key cant be null