... constraints such as the uniqueness of usernames Building Java Enterprise Applications Volume I: Architecture 47 problems don't occur in your applications. Example 3-6, then, is a SQL script ... check out Appendix C. Building Java Enterprise Applications Volume I: Architecture 50 users. However, you can use the default organizational unit of People for this task. [7] Each user will ... in Figure 3 -7 shows the tables and relationships created by the script detailed in Example 3-3 (as well as those in Appendix A). Building Java Enterprise Applications Volume I: Architecture...