What is the correct way to declare a primary key in MySQL?

Question

MySQL

Hello colleagues!
What is more correct:

create table users(
user_id 
user_login
PRIMARY_KEY(user_id, user_login)
)

Or

create table users(
user_id PRIMARY_KEY 
user_login UNIQUE
)

?
I deliberately omitted most of the operators.
I would like to thank everyone in advance who will help.

Answer 1

or. only the syntax must be correct