Question

Refer to the Teacher and Class tables. What is the result of the SET NULL foreign key action when Bryan McNeal's TeacherID is changed to 45672? (Ch.2)

Answer 1

The SET NULL foreign key action sets the foreign key column to NULL in the related table when the foreign key value is changed.

Step-by-step explanation:

The SET NULL foreign key action is used when a foreign key value is changed, and it sets the corresponding foreign key column to NULL in the related table. In the given scenario, when Bryan McNeal's TeacherID is changed to 45672, the TeacherID in the Class table will be set to NULL. This means that the teacher assigned to Bryan McNeal's class will no longer have a valid reference in the Teacher table.