ER Exercises  Exercise ER-1  What is the cardinality and
existence of each of the following relationships in just the
direction given? State any assumptions you have to make.    1.
Husband to wife   2. Student to degree   3. Child to parent   4.
Player to team   5. Student to course  Answer to Exercise ER-1
Exercise ER-2  For each of the following pairs of rules,
identify two entity types and one relationship. State the
cardinality and existence of the relationship in each case. If
you don't think enough information is available to define either
of these, then state an assumption that makes it clear. Draw the
ER diagram.    1. A department employs many persons. A person is
employed by, at most, one department.   2. A manager manages, at
most, one department. A department is managed by, at most, one
manager.   3. An author may write many books. A book may be
written by many authors.   4. A team consists of many players. A
player plays for only one team.   5. A lecturer teaches, at
most, one course. A course i