1. An enterprise key is a primary key whose value is unique for a given relation.
A. True
B. False
2. A composite attribute does not get mapped into a relation.
A. True
B. False
3. A relation is a two-dimensional table.
A. True
B. False
4. Weak entities do not get mapped into a relation.
A. True
B. False
5. A primary key may be null.
A. True
B. False