CA ERwin Data Modeler r8 New Feature Guided Tours › Diagrams, Subject Areas, Layout, and Customization › Diagram and Subject Area Properties

Diagram and Subject Area Properties

Use the following steps to become familiar with the new diagram and subject area properties.

1. Create a new model. Select the Subject Area tab in the Model Explorer and note that NO “Main Subject Area” has been created – unlike when using older versions of CA ERwin Data Modeler (r8 does not require that a model contain any subject areas. Also, both the model and subject areas may own diagrams although the presence of diagrams is completely optional). Now select the Model tab in the Model Explorer.
2. Create four entities in the model using the Model Explorer (right-click the Entities category and select New).

   Note: The entities created do not automatically display on the visible diagram.

3. In the Model Explorer, right-click one of the new entities you created. From the submenu displayed, select Add To Diagram and the entity becomes visible on the diagram. Create another new entity by selecting the Entity Tool on the toolbar and then clicking on a blank area within the diagram.

   Note: This new entity is automatically added to the diagram and to the Model Explorer.

4. Right-click on a blank area within the diagram and click Properties from the pop-up menu to launch the Diagram Editor. Select the Members tab and note that the two entities visible on your diagram display in the Included Objects list and the three remaining entities display in the Available Objects list. Add one or more available entities to your diagram and close the editor to verify your changes. You may have to move entities around to see them all as some overlap may occur.

   Note: Diagrams can only display model objects that belong to the diagram’s owner (either the Model or a Subject Area).

5. Add one or more key and non-key attributes to each of the entities visible on your diagram and connect the entities using a mixture of identifying and non-identifying relationships. Open the Diagram Editor and turn on display of Data Type and Null Option on the Entity tab (Display Attribute Data Type and Display Attribute Null Option) and/or the Table tab (Display Column Data Type and Display Column Null Option). Close the Diagram Editor and examine the effect of your selections.
6. Reopen the Diagram Editor and select Show Attributes/Columns as Grid on either the Entity or the Table tab. Close the Diagram Editor and verify the effect of this new selection. Explore the additional diagram options available within the Diagram Editor (these include options for display, print, and page setup).
7. Create a new subject area using the Model Explorer (right-click the Subject Areas category and select New) and then enter “Test” as the name for your new subject area (SA). Right-click “Test” and click Properties from the pop-up menu to open the Subject Area Editor. On the Members tab select the three entities from the Available Objects list to be included in the subject area (must be moved to the Included Objects list). Close the Subject Area Editor and observe the results of your actions.
8. While still viewing your new SA diagram, create a new diagram (refer to Step 4) and name this diagram “One Entity” by clicking on the diagram name in the upper portion of the dialog and typing the new name. Add one of your entities to this diagram, close the Diagram Editor and view the result.

   Note: You can easily switch between diagrams by selecting the appropriate named tab at the bottom left of your workspace.

9. Create a new diagram in the "Test" SA using Model Explorer (right-click ER Diagrams and select New), and add some entities to the diagram (see step 8). You can easily switch between diagrams within a subject area by selecting the tab containing the diagram name (at the bottom left of the workspace).
10. Save your model to use later.