Create a class at any hierarchy level for a custom model. Optionally, you can add a previously created class.
For example, in the Access database example, you want to add an AccessTableColumn class as a subclass to the AccessTable class. You must select the AccessTable class to create a subclass for AccessTable.
To create a class:
On the Model tab, select the model or class under which you want to create the class.
If you select the model or class in the Model navigator, click Actions > New > Class.
The New Class window appears.
If you selected a model in the Model navigator, a different New Class window appears.
Enter the class properties.
Click OK.
Metadata Manager creates the class at the selected level of the hierarchy. After you create the class, configure the class properties and relationships.