You can waste away many hours laying out the elements on a diagram. Therefore, this aspect of modeling can be time-consuming. However, a model serves as a documentation and a communication device. Therefore, taking time to ensure that it is well annotated and clearly designed is important. Most of the controls for the models are on the context menu, allowing you to modify individual aspects of the diagram. The context menu changes depending on whether you have an object or line selected, or you're just clicking in the open space. You can also set general defaults by navigating to Tools | Preferences | Data Modeler. In this section, we'll look at the various options available when working with the diagrams.
Before moving a relationship line, entity, or table, you can dramatically change the impact and readability of a large diagram just by changing the colors. This is readily demonstrated when importing from two or more schemas. Using the previous example where we imported from two schemas, open one of the subviews and select all the tables. With the objects selected, invoke the Format Object dialog using the context menu:
When working with a large number of items in a model, it's important to keep the layout organized. A variety of tools to help with the process are explained in the following sections.
Change the amount of detail displayed in a table (or entity) using the View Details menu. It is invoked with a right-click on the white space of a diagram. The View Details menu has options to display:
- All Details
- Names Only
- Columns
- Datatype
- Keys
If you have a large diagram and want to see how tables or entities relate to each other, you can create a more compact model using a display without impacting the main model. This can be done by setting the details to display only the name and then resizing and repositioning the objects.
In the following screenshot, we have set the model to display only the name of the tables. Create a more compact diagram by resizing one of the tables to a more fitting set of dimensions, select the rest, and then resize them all to the same width and height:
