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The sample tables illustrated in this appendix are used in examples throughout the library. These tables simulate a database created for use in organization or project management applications. As a group, the tables include information that describes employees, departments, projects, and activities. Figure 57 shows the relationships among the tables. These relationships are established by referential constraints, where a foreign key in the dependent table references a primary key in the parent table. In the figure, the referential constraint is symbolized by lines joining the keys; the arrowheads point from the primary key to the foreign key. Only those columns named as foreign or primary keys are listed in the figure. All tables have additional columns. You can easily review the contents of any table by executing an SQL statement, such as SELECT * FROM SQLDBA.DEPARTMENT.
Figure 57. Relationships among Tables in the Sample Application