[Middlegen-user] Howto disable CMR ?

Discussion:

David Nouls

2002-08-30 06:32:02 UTC

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

David Nouls

2002-08-30 06:43:05 UTC

Permalink

Also note: I give the foreign keys a unique name in the table fieldname.

/)avid

-----Original Message-----
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 ?
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).
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
-------------------------------------------------------
This sf.net email is sponsored by: OSDN - Tired of that same old
cell phone? Get a new here for FREE!
https://www.inphonic.com/r.asp?r=sourceforge1&refcode1=vs3390
_______________________________________________
middlegen-user mailing list
https://lists.sourceforge.net/lists/listinfo/middlegen-user

David Nouls

2002-08-30 07:03:02 UTC

Permalink

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.

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.

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-----
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

Post by David Nouls
Also note: I give the foreign keys a unique name in the table fieldname.
/)avid

middlegen.MiddlegenException: There is