# Relational Databases: Quiz 1

Name: _________________________________

One point for each possible correct answer unless otherwise indicated.

1. Which of the following are true of referential integrity?
   1. For every (non-null) primary key there is a foreign key with that value.
   2. For every (non-null) foreign key there is a primary key with that value.
   3. There must be no foreign keys.
   4. All primary keys must be non-null.
   5. All foreign keys must be non-null.