Database Modeling and Design - Database Systems - page 98

Note that the UML notation makes a distinction between a component relationship
and an aggregation relationship. In the case of the component relationship, the
constituent object types are existence dependent on a main object type. In the case of an
aggregation relationship, the constituent object types are existence independent of the
aggregation object type. Figure 5-10 illustrates the UML diagram for the (partial) college
database model that was introduced in chapter 3 (Figure 3-11). Notice that except for the
StudentEmployee object type, which has been omitted, the information represented is
essentially similar to what was represented in Figure 3-11. The only difference here is that
the appropriate UML symbols have been used.
Figure 5-10. UML Diagram for a Partial College Database Model