Business rules are logical constructs that express how a business uses its data. You can set built-in referential integrity actions to capture common business rules that apply to the relationships between data in different entities or tables. You can enforce these rules using referential integrity trigger actions. These actions tell the database management system what action to take when you attempt to delete, insert, or update a row in an entity or table.
The types of referential integrity trigger actions that you can define for the relationships in your model include:
Prevents you from deleting, inserting, or updating an instance in the parent or child entity or table if there are one or more related instances in the child or parent entity or table.
Specifies that when an instance in the parent entity or table is deleted, inserted, or updated, each related instance in the child entity or table is also deleted, inserted, or updated.
Specifies that when an instance in the parent entity or table is deleted, inserted, or updated, the foreign key attributes or columns in each related instance of the child entity or table are set to Null.
Specifies that when an instance in the parent entity or table is deleted, inserted, or updated, the foreign key attributes or columns in each related instance of the child entity or table are set to the specified default value.
Specifies that when an instance in the parent entity or table is deleted, inserted, or updated, no action is taken in each related instance of the child entity or table.
Specifies that no referential integrity action is required.
You can optionally display the referential integrity symbols for a relationship at both the child and parent end of a relationship line. If you do not see the referential integrity symbols on your diagram window, you must set the Referential Integrity Display options.
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