How to add named not null constraint

Question

I am trying to add a NOT NULL constraint by the name 'NN_Grade' in existing column 'grade'. but not able to do getting error -

My question is -

Add a constraint (NN_Grade) in table Empl that declares column Grade NOT NULL.

My Command which I tried-

ALTER TABLE students ADD CONSTRAINT NN_Grade NOT NULL(adm_no);

Error -

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'NOT NULL(adm_no)' at line 1

Need guidance

Answer 1

ALTER TABLE students ADD CONSTRAINT NN_Grade CHECK (adm_no IS NOT NULL);