Now that you have created the simplified overview diagram of your data model, you can use the diagram palette to add notes and objects to your data model. The diagram editor can help you visualize the changes to your data model and how the objects in the model interact. By adding a column to the EMP_EMPLOYEE_DIM schema, you can track the middle initial of each employee. You can later use this middle initial column to make unique foreign-key and primary-key relationships between data objects.
Some of the objects on the palette are used for annotation only, and do not change the underlying data model. For example, you can add notes or text objects to the diagram to document information about model objects or relationships. You can also add geometric shapes to the diagram that contain text or that visually group diagram objects together. You can modify the display characteristics of the diagram by changing font or color options, or by changing diagram properties in the Properties view. All of these options change the diagram properties, but do not modify the underlying data model.
The Data area of the palette contains data model objects. When you add or modify data model objects by using the palette or the diagram surface, you modify the underlying data model. Changes that you make to data objects in a diagram are automatically saved to the diagram, but you must explicitly save the model file to save the changes to the model.
In the Properties view, you can view and modify the properties of data model objects. Typically, you use the diagram editor and the Properties view together to modify data model objects. When an object is highlighted in either a diagram or the Data Project Explorer, the Properties view changes to show the properties of that object.
To add relationships between tables by using the overview diagram and the Properties view: