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RE: InstantDB: Problem with updates and foreign keys (Beta 2)


Is this something that can be fixed in the next beta as this problem makes
FK's pretty much unusable?

Thanks
James

-----Original Message-----
From: owner-instantDB@enhydra.org [mailto:owner-instantDB@enhydra.org]On
Behalf Of Peter Hearty
Sent: Tuesday, September 19, 2000 1:49 PM
To: instantDB@enhydra.org
Subject: Re: InstantDB: Problem with updates and foreign keys (Beta 2)


James

Looks like a bug. InstantDB implements updates by doing a delete followed by
an insert. It's probably failing on the delete part because it hasn't
checked that the subsequent insert has a valid value that will restore the
referential integrity.

Regards

Pete

--

Peter Hearty                         peter.hearty@lutris.com
Lutris Technologies (UK)        http://www.lutris.com
----- Original Message -----
From: "James Medlock" <jmedlock@tenornetworks.com>
To: <instantdb@enhydra.org>
Sent: Tuesday, September 19, 2000 6:15 PM
Subject: InstantDB: Problem with updates and foreign keys (Beta 2)


> When I try and do an update of a row in a table for which there is a
foreign
> key reference, I get an exception stating that "Cannot delete value, XXX.
In
> use by column A.B".
>
> Am I doing something wrong, or can Foreign Keys not be used in tables that
> are being updated?
>
> Thanks
> James
>
> --
>
> Example:
>
> ; First load the JDBC driver and open a database.
> d org.enhydra.instantdb.jdbc.idbDriver;
> o jdbc:idb=blah.prp;
>
> ; Record all results
> e SET EXPORT "export0.txt" FIXEDLENGTH COLNAMEHEADER ROWNUMBERS CONTROLCOL
> SUMMARYHEADER;
>
> e create table BAR (
>   ID int,
>   NAME CHAR(32)
> );
>
> e create table FOO (
>   ID int foreign key references BAR(ID) on delete cascade,
>   NAME char(32)
> );
>
> e insert into BAR(ID, NAME) values(101, "fred");
> e insert into BAR(ID, NAME) values(102, "joe");
>
> e insert into FOO(ID, NAME) values(101, "fred2");
> e insert into FOO(ID, NAME) values(102, "joe2");
>
> ; This fails with "Cannot delete..." exception
> e update BAR set NAME="newfred" where ID=101;
>
> ; The End
> c close;
>
> --------------------------------------------------------------------------
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>

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