NOTE: Although relationship classes can be both created and edited in ArcInfo and ArcEditor, they are read-only in ArcView. The feature classes participating in a relationship class will also be read-only in ArcView.

When you create a relationship class, you create it with an initial cardinality, such as one-to-many or many-to-many. In a real system, however, relationship cardinalities are more specific. Once you've created the relationship class, you can refine the cardinality by creating rules. Relationship rules allow you to restrict the type of objects in the origin feature class or table that can be related to a certain kind of object in the destination feature class or table.

For an illustration of this task, click here.

1. Right-click the relationship class in the ArcCatalog tree.
2. Click Properties.
3. Click the Rules tab.
4. If your origin class has subtypes, click the subtype to which you want to associate a relationship rule. If the origin class has no subtypes, the relationship rule will apply to all features.
5. If the destination class has subtypes, check the subtype that you want to relate to the selected subtype in the origin class. If the destination class has no subtypes, the relationship rule will apply to all features.
If one or both sides of the relationship class is many, you can limit the specific range of cardinality. In this example, the origin side of the relationship is one, so you can't modify its range. However, the destination side is many, so you can modify its range.
6. Check the check box to specify the range of destination objects per related origin objects.
7. Click the up and down arrows to increase or decrease the minimum and maximum number of related destination objects.
8. Repeat steps 4 through 7 until you have specified all the relationship rules for this relationship class. Click OK or Apply to create the rules in the database.

Tip Once a relationship rule is added to a relationship class, that rule becomes the only valid relationship that can exist. To make other relationship combinations and cardinalities valid, you must create additional rules.