Disallow NULL values with SET NOT NULL
The professors table is almost ready now. However, it still allows for NULLs to be entered. Although some information might be missing about some professors, there's certainly columns that always need to be specified.
This exercise is part of the course
Introduction to Relational Databases in SQL
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
-- Disallow NULL values in firstname
___ ___ professors
ALTER COLUMN ___ SET NOT NULL;