Database Reference
In-Depth Information
Figure 12-27.
The “Learn By Doing” version of the Northwind data warehouse
Parent-Child Dimensions
Parent-child dimensions are created using a table that is self-referencing. The DimEmployees table has a
manager key that references the employee key (Figure
12-28
). This relationship indicates which employee
manages other employees.
For example, the record for Nancy Davolio and several others have a ManagerKey of 11. And the record for
Andrew Fuller has an EmployeeKey value of 11. Therefore, number 11 (Andrew Fuller) is listed as the manager
for Nancy, Janet, Margaret, Steven, and Laura. One employee, Stephen Buchan—who is managed by Andrew
Fuller—is the manager of three other employees: Michael, Robert, and Anne. This means there are three levels
of organization between the employees: a manager, an assistant manager, and individual employees. And
apparently Andrew Fuller has no one else overseeing him. He is his own boss.
