What do you mean by Cascading Referential Integrity Constraints?

What do you mean by Cascading Referential Integrity Constraints?

Right now only two new clouses are there, Which is : ON DELETE and ON UPDATE clauses in the REFERENCES clause of the CREATE TABLE and ALTER TABLE statements.
         The ON DELETE and ON UPDATE clauses have two options:
� NO ACTION : NO ACTION specifies that the deletion/updation fail with an error.
� CASCADE : CASCADE specifies that all the rows with foreign keys pointing to the deleted/updated row are also deleted / updated.
> ON DELETE : Its bassically controls what actions are taken if we attempt to delete a row to which existing foreign keys point.

> ON UPDTE : It is bassically defines the actions that are taken if we attempt to update a candidate key value to which existing foreign keys point.

By:UMANG
Date:2014-01-09 00:00:00

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