This illustration shows the database schema for the HR application. Every business object has a system-defined Id field. The Location business object has one user-defined field, Name. The Department business object has two user-defined fields, Name and Location. The Employee business object has four user-defined fields: Name, Department, Hire Date, and Email. At the bottom of each business object is the accessor name for the referenced business object, if there is one. A Location can have any number of Departments. A Department can have zero or one Location. A Department can have any number of Employees. An Employee can have zero or one Department.