Chapter 1 homework:
1. What column(s) make up the primary key of the GRADE table?
2. How many foreign keys does the ENROLLMENT table have?
3. Explain recursive/self-referencing relationship using the relevant table and column(s)
from the STUDENT schema.
4. Explain the relationship(s) the GRADE TYPE WEIGHT table has to other table(s).
5. Can a foreign key column in a table accept any data value? Explain using the relevant
tables from the STUDENT schema.