
your own. Regardless of how many values are displayed on the diagram, all the values
you enter in the constraint are included for DDL generation purposes.
5.2 Internal and External Uniqueness Constraints
The previous chapter showed how to use the Fact Editor to add uniqueness and manda-
tory role constraints to a single predicate. For these two kinds of internal constraint, the
Fact Editor usually provides the easiest way to add the constraints. All other role-based
constraints are best added and edited using the Add Constraint dialog. Although you
5.2 Internal and External Uniqueness Constraints 99
Figure 5–1 Half-way through adding an {‘M’,’F’} value ...