Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
Home -> Community -> Usenet -> c.d.o.server -> Re: FOREIGN KEY
Hi Francesco
On update cascade is not supported as a column/table constraint. You can
implement
it by using triggers. It is very popular and there are plenty of "how to do"
notes around.
I recall Thomas Kyte has something about it on his site. See T.K's messages.
Karen Abgarian.
francesco wrote:
> I am setting a database under Oracle 8.
> I need to link two tables (father and child) with a FOREIGN KEY
>
> So far I have done:
> child table
> CREATE TABLE PROG
> (ID_PROG VARCHAR2(5),
.ID_BEN VARCHAR2(50));
>
> father table
> CREATE TABLE BEN(ID_B VARCHAR2(5), ...);
>
> foreign key
> ALTER TABLE PROG ADD CONSTRAINT FK_IDBEN_PROG FOREIGN KEY (ID_BEN)
> REFERENCES BEN (ID_B) ON DELETE CASCADE;
>
> The question is: is it available the SQL keyword ON UPDATE CASCATE
> (instead of ON DELETE CADSCADE) in the CONSTRAINT statement? Standard
> SQL books say its a possible option, but I have found nothing in Oracle
> documentation and SQL*Plus does not accept it.
>
> If it is not possible, which is the best way to change ID_B in BEN table
> and consequently ID_BEN in PROG table? Just by code, inserting new
> record in father table (the same field values except ID_B), change
> related records in child table, delete old record in father table?
> PS: I use Delphi 3 as client application environment.
>
> Thanks in advance
Received on Thu Aug 26 1999 - 14:01:40 CDT