In the last exercise, you created a physical data model and an
overview diagram of the data model. You can use diagrams in the workbench
to visualize and modify data models. The default overview diagram contains
all objects that are contained in the SAMP schema. However, when you are working
with a large data model, you can create simplified overview diagrams so that
they contain only the objects that you are interested in. You can create multiple
diagrams for one data model, each with different objects.
In this exercise, you will create a new overview diagram that contains
two tables.
To create a simple overview diagram:
- Close the SAMP diagram that was generated in the last exercise. Leave the sample_model physical data model file open in the physical
data model editor. To view or modify objects in a data model, the model must
always be open in the editor.
- In the Data Project Explorer, expand the Data Models folder,
the sample_model.pdm node, the SAMPLE database node, and the SAMP schema node.
- Right-click the Diagrams folder under the
SAMP schema node, and select New Overview Diagram. As an alternative to these steps, you could select New Blank
Diagram, and then drag and drop objects from the Data Project
Explorer to the diagram surface.
- In the window that opens, specify the following settings:
- Type mySAMP in the Diagram name field.
- Select the check box next to the EMP_PHOTO, EMP_RESUME, EMPLOYEE,
and DEPARTMENT tables.
- Click OK.
The new mySAMP diagram opens in the diagram editor, and is displayed
in the Data Project Explorer in the
Diagrams folder.
Tip: Move the tables in the diagram closer together so that you can
see them all at the same time. This will help in the next exercise when you
draw relationships between objects. You can use the shaded box in the Outline
view to move the focus in the diagram, then highlight diagram objects and
drag them to move them.