Create two foreign key constraints with on update/delete cascade - sql

Question

Example of database (SQL Server):
Table A
-colA (PK, int)
Table B
-ColB (FK, int) --> points to Table X
Table C
-ColAC (PK, FK, int not null) --> points to Table A
-ColBC (PK, FK, int not null) --> points to Table B
Table C's primary key is both ColAC and ColBC. Each column has foreign key that points to a different table. I need to have ON UPDATE/DELETE CASCADE constraints on both foreign keys for Table C. So when either Table A or B has changes then it is cascaded in Table C.
Table A and B are already in use. I can create Table C with only either one of the constraints but not both, this will return an error message. How do I create both FK constraints?
Example of SQL:
CREATE TABLE Table_C (
ColAC INT NOT NULL,
ColBC INT NOT NULL,
PRIMARY KEY (
ColAC,
ColBC
)
)
GO
ALTER TABLE Table_C WITH CHECK ADD FOREIGN KEY (ColAC)
REFERENCES Table_A (ColA)
ON UPDATE CASCADE
ON DELETE CASCADE
GO
--The second constraint will always fail (does not matter which one is first).
ALTER TABLE Table_C WITH CHECK ADD FOREIGN KEY (ColBC)
REFERENCES Table_B (ColB)
ON UPDATE CASCADE
ON DELETE CASCADE
GO
Error message:
Introducing FOREIGN KEY constraint .... on table 'Table_C' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.

Answer 1

You can go for two different tables, instead of single TableC
Table C1
-ColAC (PK, FK, int not null) --> points to Table A
Table C2
-ColBC (PK, FK, int not null) --> points to Table B
Now, you can have UNION ALL between these two tables
CREATE VIEW vw_TableC
AS
SELECT ColAC, 'TableA' as parent ... FROM TableC1
UNION ALL
SELECT ColBC, 'TableB' as parent ... FROM TableC2