Which of the following correctly describes the referential action specified by the ON UPDATE CASCADE subclause of
Question:
Which of the following correctly describes the referential action specified by the ON UPDATE CASCADE subclause of the FOREIGN KEY clause?
1.If a row from the parent table is deleted then matching rows in the child table are automatically deleted as well.
2. If a row from the parent table is updated, then matching rows in the child table are automatically updated as well.
3. If a query attempts to delete a row from the parent table while tuples in a child table are dependent on it then the query will be rejected by the DBMS.
4. If a query attempts to update a row from the parent table while tuples in a child table are dependent on it then the query will be rejected by the DBMS.
5. If a row from the parent table is updated, then matching rows in the child table are automatically set to NULL.