Relationships

Relationships are a bit more complex than they seem at first. Relationships carry information that describes the rules of the business and the constraints on creating, modifying, and deleting instances. For example, you can use cardinality to define how many instances are involved in both the child and parent entities in the relationship. You can also specify how you want to handle database actions such as INSERT, UPDATE, and DELETE using referential integrity rules.

Data modeling also supports highly complex relationship types. Relationship types let you construct a logical model of your data that is understandable to both business and systems experts.

This section contains the following topics

Relationship Cardinality

Referential Integrity

Additional Relationship Types