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.
Latihan ini adalah bagian dari kursus
Introduction to Relational Databases in SQL
Latihan interaktif praktis
Cobalah latihan ini dengan menyelesaikan kode contoh berikut.
-- Disallow NULL values in firstname
___ ___ professors
ALTER COLUMN ___ SET NOT NULL;