Thanks Aslak,

I now understand what was going wrong. I'll check today if your fixes indeed
work in my situation.

/)avid

> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Aslak
> Helles�y
> Sent: Saturday, August 31, 2002 11:35 PM
> To: David Nouls; M-Leander Reimer
> Cc: Middlegen Users Mailing List
> Subject: RE: [Middlegen-user] Howto disable CMR ?
>
>
> Hi!
>
> Your problem should be fixed now. Details below.
>
> Aslak
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of David
> > Nouls
> > Sent: 30. august 2002 11:07
> > To: M-Leander Reimer
> > Cc: Middlegen Users Mailing List
> > Subject: RE: [Middlegen-user] Howto disable CMR ?
> >
> >
> > Hi Leander,
> >
> > No, that didn't help. I still get the same error message.
> > If I look to the samples of middlegen I see no example where they name
> > the relations. They never reference the same table more than once.
> >
>
> The error message is misleading. Naming the relations won't help.
>
> > This is rather stupid that the middlegen task just stops. The foreign
> > keynames are different so it should be no problem to differentiate the
> > relations.
> >
>
> Should be fixed now. If you're interested in the inner workings, read on.
>
> A foreign key is not the same as a foreign key column. In fact, a foreign
> key is a set of one or more foreign key columns. In most cases a
> foreign key
> consists of only one foreign key column, so people tend to mix them
> up. -Even the people who write JDBC drivers.
>
> So what does the name of a foreign key mean? Well, it's just a
> logical name.
> This name can be used to figure out to what foreign key a certain foreign
> key column belongs to. This is needed when there are more than
> one relation
> between 2 tables. In your scenario, we need to know whether the
> two foreign
> key columns belong to the same logical key or whether it is two distinct
> foreign keys with only one column.
>
> Middlegen uses the key name (FK_NAME) to figure that out. The
> mm.mysql JDBC
> driver reports null for FK_NAME, so it panics because it can't figure it
> out.
>
> I have just committed updated code that can do without this FK_NAME, which
> many drivers report to be null. The new approach is to use
> KEY_SEQ. Look in
> MiddlegenPopulator.addRelations(...) if you're interested.
>
> > The whole joke is ofcourse that I only need CMP and not CMR! I never use
> > finders
> > since I can get a speed x3 when I use a DAO approach. EJB QL is a
> > nice idea,
> > but
> > needs a few more revision to make it useful for real applications.
> >
> > I'm also deploying on JBOSS 3.0.1 so that means I can not have
> > foreign keys
> > that
> > are part of a relation (every one of them). But I don't want to
> call into
> > the
> > Local object of a relation to just get the id!
> >
> > /)avid
> >
> > > -----Original Message-----
> > > From: M-Leander Reimer [mailto:[EMAIL PROTECTED]]
> > > Sent: Friday, August 30, 2002 10:44 AM
> > > To: David Nouls
> > > Subject: RE: [Middlegen-user] Howto disable CMR ?
> > >
> > >
> > > Hi David,
> > >
> > > I think the problem is that you define your foreign keys with
> the ALTER
> > > TABLE style. This does not work work mySql for some reason.
> > >
> > > Try to define the foreign keys in the CREATE TABLE definition, as its
> > > done in the middlegen samples.
> > >
> > > Worked for me (and I am using the same configuration as you do :-))
> > >
> > > Hope it helps.
> > >
> > > Leander
> > >
> > >
> > > Am Fre, 2002-08-30 um 10.47 schrieb David Nouls:
> > > > Also note: I give the foreign keys a unique name in the table
> > fieldname.
> > > >
> > > > /)avid
> > > >
> > > > > -----Original Message-----
> > > > > From: [EMAIL PROTECTED]
> > > > > [mailto:[EMAIL PROTECTED]]On
> > Behalf Of David
> > > > > Nouls
> > > > > Sent: Friday, August 30, 2002 10:36 AM
> > > > > To: Middlegen Users Mailing List
> > > > > Subject: [Middlegen-user] Howto disable CMR ?
> > > > >
> > > > >
> > > > > Hello,
> > > > >
> > > > > Is there a way to disable the CMR detection of Middlegen ?
> > > > > I always get the following error:
> > > > >
> > > > >
> > > > > BUILD FAILED
> > > > > file:C:/Dev/project/build.xml:204:
> > > middlegen.MiddlegenException: There is
> > > > > more
> > > > >  than one relation between bug and person, but the JDBC
> > > driver or database
> > > > > doesn
> > > > > 't seem to provide any names for the relationships. It is
> therefore
> > > > > impossible f
> > > > > or Middlegen to determine what foreign keys participate in what
> > > > > relationships. Y
> > > > > ou should try a different JDBC driver or reduce the number of
> > > relations to
> > > > > one.
> > > > > You can also try to explicitly name the relations in the database.
> > > > > DatabaseMetad
> > > > > ata.getCrossReference(...).getString("FK_NAME") + returned null!
> > > > >
> > > > >
> > > > > I'm using the MySql driver that is used in the samples. I
> > > tried with other
> > > > > versions
> > > > > of the driver as well, yet I don't seem to be able to get the
> > > relations
> > > > > working
> > > > > correctly.
> > > > >
> > > > > I don't realy need the CMR stuff anyway, so I don't want to
> > > > > invest too much
> > > > > time
> > > > > in getting them to work.
> > > > >
> > > > > Any ideas ?
> > > > > - I'm using MySQL (latest 3.x release) MAX with InnoDB enabled
> > > > > - Java 1.3
> > > > > - Jboss 3.0.1 with CMP.
> > > > >
> > > > > (No i'm not switching to a better database, MySQL is just fine
> > > > > for what I'm
> > > > > doing
> > > > > it is more stable and faster than PostgresSQL).
> > > > >
> > > > > The create.sql that I use has the following foreign keys defined:
> > > > > ALTER TABLE BUG
> > > > > ADD CONSTRAINT FK_PERSON_BUG_1
> > > > > FOREIGN KEY (idAssignedTo) REFERENCES PERSON (idPerson);
> > > > >
> > > > > ALTER TABLE BUG
> > > > > ADD CONSTRAINT FK_PERSON_BUG_8
> > > > > FOREIGN KEY (idReportedBy) REFERENCES PERSON (idPerson)
> > > > > ;
> > > > >
> > > > > So, as you can see: i do specify the names of the relations,
> > > but these are
> > > > > not returned
> > > > > by the JDBC driver. (I know the names stink but my
> > generator makes the
> > > > > scripts for me,
> > > > > in de design tool I set the names correctly).
> > > > >
> > > > > /)avid
> > > > >
> > > > >
> > > > >
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> > > Dipl.-Inf. (FH)
> > >
> > > Techdivision
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