Meyer-Willner, Bernhard
2002-11-18 04:30:02 UTC
Hi there,
more to this issue! Yes this is not possible with JBoss. I found out a few
weeks a go and it took me just too long to get behind this. It should be
possible in JBoss to defer the INSERT until ejbPostCreate which it can't do
right now. There's a patch (request Id 612033 (CMR:foreign key as part of
primary key)) on sourceforge which claims to fix a problem which has to do
with this (a field that his both CMR and CMR). Maybe this help anybody. I
had an exchange with JBoss developers and they thought this issue could be
fixed by version 3.2 which should be out in January 03. Let's see, till then
disabling the not null contraint or trying the deferred option in Oracle
seems to be the only option.
BTW, a while ago I posted a report on this issue in this mailing list :)
Cheers,
Bernie
-----Ursprüngliche Nachricht-----
Von: Gavin Hughes [mailto:***@mynrma.com.au]
Gesendet: Montag, 18. November 2002 00:05
An: middlegen-***@lists.sourceforge.net
Betreff: RE: [Middlegen-user] CMR in ejbPostCreate and NOT NULL foreign keys
This is a JBoss problem, so I don't think there is anything you can do about
it in Middlegen.
JBoss does an INSERT after ejbCreate - as you are supposed to set CMR's in
ejbPostCreate
this results in an error as the FK field(s) are null at this point.
You could try to work around this by declaring the foreign key(s) as CMP
fields as well as CMR
fields then setting the fk in ejbCreate - except that JBoss doesn't allow
fields to be defined as
CMP and CMR.
There has been plenty of discussion on the topic on the JBoss mailing lists
- at this point
the usual recommendation is "don't define your foreign keys as NOT NULL".
You can still keep your foreign key definitions - just define the
constraints as deferrable, so
they aren't checked until the "commit" (instead of happening after the
insert in ejbCreate).
For example (this works on Oracle) :
ALTER TABLE LOCATION ADD CONSTRAINT FK_LOCATION_COUNTRY_ID
FOREIGN KEY (country_id)
REFERENCES COUNTRY (id)
INITIALLY DEFERRED DEFERRABLE;
The following post suggests there is a patch for JBoss that fixes the
problem - but
according to the details for this patch on sourceforge it doesn't actually
work :-(
http://www.mail-archive.com/jboss-***@lists.sourceforge.net/msg23045.html
https://sourceforge.net/tracker/?func=detail&atid=376687&aid=630707&group_id
=22866
Cheers,
Gavin.
-----Original Message-----
From: Mustafa Radi [mailto:***@kabsi.at]
Sent: Sunday, 17 November 2002 6:48 PM
To: Russell Black
Cc: Eivind Waaler; middlegen-***@lists.sourceforge.net
Subject: Re: [Middlegen-user] CMR in ejbPostCreate and NOT NULL foreign keys
yes - I think you are right, I had the same problems and had to remove the
NOT NULL statements in the database with jboss. Since jboss doesn't support
the fkcmp="true" there is even no way to set this value at least to the
right
value when creating an EntityBean. The question is - where is the bug !!!
Currently
I don't believe its a middlegen problem ...
cheers
Russell Black wrote:
No, I left fkcmp="true". Without that the struts won't compile. Anyway
asyou said, that wouldn't help about the keys being set to null.It seems
like this would be a problem intrinsic to all J2EE implementations,since:a)
The J2EE container doesn't know the FK information until ejbPostCreate
iscalled, andb) the INSERT statement happens before ejbPostCreate, therefore
it *has* toinsert NULL for the foreign keys, violating the NOT NULL
constraint socommon on foreign keys.Since Sun obviously thought this issue
out, there is probably an error in mylogic above. Can anyone see it? Is
anyone else having this problem?Thanks,Russell----- Original Message
-----From: "Eivind Waaler" <***@tihlde.org>To: "Russell Black"
<russell.black
@iarchives.com>Cc: <middlegen-***@lists.sourceforge.net>Sent: Saturday,
November 16, 2002 8:21 AMSubject: Re: [Middlegen-user] CMR in ejbPostCreate
and NOT NULL foreign keys
Hmm, according to the SQL you're printing out there the two foreign keysare
being set twice in the same statement. Are you using thefkcmp="false"
attribute in your cmp20 plugin? Read the documentation aboutthis attribute
here:http://boss.bekk.no/boss/middlegen/plugins/cmp20.html#fkcmpI guess that
wouldn't help about the keys being set to null, weird wehaven't seen this
error before though. I'll look into it on my examplerunning on
weblogic..Regards.eivindOn Fri, 15 Nov 2002, Russell Black wrote:
I know the spec says that CMR fields should be set in the post-create
method, but it causes a problem when your table has a NOT NULL constraint
onthe foreign key (CMR) column. Incidentally the airlines example
suffersfrom this problem. I believe the issue is this: consider the
followingtable:
CREATE TABLE "reservations"( "reservation_id" INT NOT NULL, "person_id_fk"
INT NOT NULL, "flight_id_fk" INT NOT NULL, "comment" VARCHAR, PRIMARY KEY
("reservation_id","person_id_fk","flight_id_fk"), FOREIGN KEY
("person_id_fk") REFERENCES "persons"("person_id"), FOREIGN KEY
("flight_id_fk") REFERENCES "flights"("flight_id"));ejbCreate is called, and
it sets the CMP fields ONLY, and it tries to do
the following SQL (copied from my JBOSS console)
INSERT INTO reservation (reservation_id, person_id_fk, flight_id_fk,
comment, flight_id_fk, person_id_fk) VALUES (5, NULL, NULL, 'A
comment',NULL, NULL)
Which fails because the foreign keys can't be null. The foreign keys
aren't going to be set until the ejbPostCreate which happens AFTER
theINSERT, so it never gets that far because the INSERT fails.
Does this imply that foreign keys can't have NOT NULL values when using
CMR? This seems bad, because the NOT NULL constraint is there for a reason.
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more to this issue! Yes this is not possible with JBoss. I found out a few
weeks a go and it took me just too long to get behind this. It should be
possible in JBoss to defer the INSERT until ejbPostCreate which it can't do
right now. There's a patch (request Id 612033 (CMR:foreign key as part of
primary key)) on sourceforge which claims to fix a problem which has to do
with this (a field that his both CMR and CMR). Maybe this help anybody. I
had an exchange with JBoss developers and they thought this issue could be
fixed by version 3.2 which should be out in January 03. Let's see, till then
disabling the not null contraint or trying the deferred option in Oracle
seems to be the only option.
BTW, a while ago I posted a report on this issue in this mailing list :)
Cheers,
Bernie
-----Ursprüngliche Nachricht-----
Von: Gavin Hughes [mailto:***@mynrma.com.au]
Gesendet: Montag, 18. November 2002 00:05
An: middlegen-***@lists.sourceforge.net
Betreff: RE: [Middlegen-user] CMR in ejbPostCreate and NOT NULL foreign keys
This is a JBoss problem, so I don't think there is anything you can do about
it in Middlegen.
JBoss does an INSERT after ejbCreate - as you are supposed to set CMR's in
ejbPostCreate
this results in an error as the FK field(s) are null at this point.
You could try to work around this by declaring the foreign key(s) as CMP
fields as well as CMR
fields then setting the fk in ejbCreate - except that JBoss doesn't allow
fields to be defined as
CMP and CMR.
There has been plenty of discussion on the topic on the JBoss mailing lists
- at this point
the usual recommendation is "don't define your foreign keys as NOT NULL".
You can still keep your foreign key definitions - just define the
constraints as deferrable, so
they aren't checked until the "commit" (instead of happening after the
insert in ejbCreate).
For example (this works on Oracle) :
ALTER TABLE LOCATION ADD CONSTRAINT FK_LOCATION_COUNTRY_ID
FOREIGN KEY (country_id)
REFERENCES COUNTRY (id)
INITIALLY DEFERRED DEFERRABLE;
The following post suggests there is a patch for JBoss that fixes the
problem - but
according to the details for this patch on sourceforge it doesn't actually
work :-(
http://www.mail-archive.com/jboss-***@lists.sourceforge.net/msg23045.html
https://sourceforge.net/tracker/?func=detail&atid=376687&aid=630707&group_id
=22866
Cheers,
Gavin.
-----Original Message-----
From: Mustafa Radi [mailto:***@kabsi.at]
Sent: Sunday, 17 November 2002 6:48 PM
To: Russell Black
Cc: Eivind Waaler; middlegen-***@lists.sourceforge.net
Subject: Re: [Middlegen-user] CMR in ejbPostCreate and NOT NULL foreign keys
yes - I think you are right, I had the same problems and had to remove the
NOT NULL statements in the database with jboss. Since jboss doesn't support
the fkcmp="true" there is even no way to set this value at least to the
right
value when creating an EntityBean. The question is - where is the bug !!!
Currently
I don't believe its a middlegen problem ...
cheers
Russell Black wrote:
No, I left fkcmp="true". Without that the struts won't compile. Anyway
asyou said, that wouldn't help about the keys being set to null.It seems
like this would be a problem intrinsic to all J2EE implementations,since:a)
The J2EE container doesn't know the FK information until ejbPostCreate
iscalled, andb) the INSERT statement happens before ejbPostCreate, therefore
it *has* toinsert NULL for the foreign keys, violating the NOT NULL
constraint socommon on foreign keys.Since Sun obviously thought this issue
out, there is probably an error in mylogic above. Can anyone see it? Is
anyone else having this problem?Thanks,Russell----- Original Message
-----From: "Eivind Waaler" <***@tihlde.org>To: "Russell Black"
<russell.black
@iarchives.com>Cc: <middlegen-***@lists.sourceforge.net>Sent: Saturday,
November 16, 2002 8:21 AMSubject: Re: [Middlegen-user] CMR in ejbPostCreate
and NOT NULL foreign keys
Hmm, according to the SQL you're printing out there the two foreign keysare
being set twice in the same statement. Are you using thefkcmp="false"
attribute in your cmp20 plugin? Read the documentation aboutthis attribute
here:http://boss.bekk.no/boss/middlegen/plugins/cmp20.html#fkcmpI guess that
wouldn't help about the keys being set to null, weird wehaven't seen this
error before though. I'll look into it on my examplerunning on
weblogic..Regards.eivindOn Fri, 15 Nov 2002, Russell Black wrote:
I know the spec says that CMR fields should be set in the post-create
method, but it causes a problem when your table has a NOT NULL constraint
onthe foreign key (CMR) column. Incidentally the airlines example
suffersfrom this problem. I believe the issue is this: consider the
followingtable:
CREATE TABLE "reservations"( "reservation_id" INT NOT NULL, "person_id_fk"
INT NOT NULL, "flight_id_fk" INT NOT NULL, "comment" VARCHAR, PRIMARY KEY
("reservation_id","person_id_fk","flight_id_fk"), FOREIGN KEY
("person_id_fk") REFERENCES "persons"("person_id"), FOREIGN KEY
("flight_id_fk") REFERENCES "flights"("flight_id"));ejbCreate is called, and
it sets the CMP fields ONLY, and it tries to do
the following SQL (copied from my JBOSS console)
INSERT INTO reservation (reservation_id, person_id_fk, flight_id_fk,
comment, flight_id_fk, person_id_fk) VALUES (5, NULL, NULL, 'A
comment',NULL, NULL)
Which fails because the foreign keys can't be null. The foreign keys
aren't going to be set until the ejbPostCreate which happens AFTER
theINSERT, so it never gets that far because the INSERT fails.
Does this imply that foreign keys can't have NOT NULL values when using
CMR? This seems bad, because the NOT NULL constraint is there for a reason.
-------------------------------------------------------This sf.net email is
sponsored by: To learn the basics of securing your web site with SSL, click
here to get a FREE TRIAL of a Thawte Server Certificate:
http://www.gothawte.com/rd524.html__________________________________________
_____middlegen-user mailing
listmiddlegen-***@lists.sourceforge.nethttps://lists.sourceforge.net/lists/
listinfo/middlegen-user
This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.