Re: auto delete and foreign keys
Hi, The problem was solved by setting the foreign key constraint to DEFERRABLE INITIALLY DEFERRED in postgres. So the check of constraints is done only at the end of the transaction, this way OJB is deleting the objects and then the constraints are enforced. Thanks for your help. Jean-Yves On 3/28/06, Jean-Yves Sironneau <[EMAIL PROTECTED]> wrote: > > Hi Armin, > > On 3/27/06, Armin Waibel <[EMAIL PROTECTED]> wrote: > > > > Hi Jean-Yves, > > > > Jean-Yves Sironneau wrote: > > > Hello, > > > > > > Yes another question again. > > > > > > I have a class Area that is referencing a class Point, and Area has a > > > foreign key constraint on Point. > > > I'am using ODMG, and i would like OJB to delete the Point when i > > delete the > > > Area. What happens is that when i commit a > > > transaction for removing an Area, OJB is trying to remove the Point > > but of > > > course it can't because the foreing key constraint is > > > violated as the Area is still referencing the point. So i suppose the > > Area > > > should be removed first for this to work. Do you think it can > > > be a bug ? Do i have to manually unreference the point somewhere ? > > > > > > > Do you use auto-delete="object" in Area 1:1 reference-descriptor to > > Point? > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Specific+Metadata+Settings > > > > > > Yes > > If you have problems with the order of persistent objects you can > > > > A. disable ordering and set object order by hand (first delete Area, > > then Point) > > > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Disable+OJB%27s+object+ordering%2C+determine+object+order+%22by+hand%22 > > > Yes, but the problem is that i do not explicitely call a delete method on > this object, > I remove an object that is referencing an Area, and the Area is > referencing the Point, > this is a "cascade" delete. > > B. use a workaround to specify the database FK. Simply set a custom > > property 'constraint' in reference-descriptor of Area. > > > > > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Foreign+Keys+Constraints+and+ODMG-api > > > > If set OJB's ordering try to take care of the database constraint. > > > I tried but it did not work, here is an extract of the sql statements > generated by OJB > > 1143500067952|0|1|statement||SELECT A0.id,A0.documentBaseId,A0.firstName, > A0.lastName ,A0.email,A0.url FROM Person A0 WHERE > A0.documentBaseId='27WXcUHNXRZ36EkQnYIQqmHsbqPqX9k9cnOoAyPgbf65g2Cqql' > > 1143500068124|161|0|statement||DELETE FROM Point WHERE id = > 'OmEWtzi9bM9etJISTKWWjKaUlmUTopM6c8W5xGQUN8yKp7HQFs' > > 1143500068206|1|0|rollback|| > > What I do not get is that the database foreign key check is deferrable > (postgres), so this statement should be ok if followed by the deletion of > the Area, but i have to look more precisely at the meaning of deferred in > postgres. > Anyway if it does not work i will try to reverse the relation and it > should work. > > Thank you. > > Jean-Yves > > > > > > Thank you. > > > > > > Jean-Yves > > > > > > P.S.: > > > > > > I'am not a foreign key constraint expert, but i tried to use > > deferrable=true > > > for this constraint and it does not work neither. > > > > strange! I would expect that in this case delete ordering is irrelevant. > > > > regards, > > Armin > > > > - > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > >
Re: auto delete and foreign keys
Hi Armin, On 3/27/06, Armin Waibel <[EMAIL PROTECTED]> wrote: > > Hi Jean-Yves, > > Jean-Yves Sironneau wrote: > > Hello, > > > > Yes another question again. > > > > I have a class Area that is referencing a class Point, and Area has a > > foreign key constraint on Point. > > I'am using ODMG, and i would like OJB to delete the Point when i delete > the > > Area. What happens is that when i commit a > > transaction for removing an Area, OJB is trying to remove the Point but > of > > course it can't because the foreing key constraint is > > violated as the Area is still referencing the point. So i suppose the > Area > > should be removed first for this to work. Do you think it can > > be a bug ? Do i have to manually unreference the point somewhere ? > > > > Do you use auto-delete="object" in Area 1:1 reference-descriptor to Point? > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Specific+Metadata+Settings Yes If you have problems with the order of persistent objects you can > > A. disable ordering and set object order by hand (first delete Area, > then Point) > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Disable+OJB%27s+object+ordering%2C+determine+object+order+%22by+hand%22 Yes, but the problem is that i do not explicitely call a delete method on this object, I remove an object that is referencing an Area, and the Area is referencing the Point, this is a "cascade" delete. B. use a workaround to specify the database FK. Simply set a custom > property 'constraint' in reference-descriptor of Area. > > > http://db.apache.org/ojb/docu/guides/odmg-guide.html#Foreign+Keys+Constraints+and+ODMG-api > > If set OJB's ordering try to take care of the database constraint. I tried but it did not work, here is an extract of the sql statements generated by OJB 1143500067952|0|1|statement||SELECT A0.id,A0.documentBaseId,A0.firstName, A0.lastName,A0.email,A0.url FROM Person A0 WHERE A0.documentBaseId='27WXcUHNXRZ36EkQnYIQqmHsbqPqX9k9cnOoAyPgbf65g2Cqql' 1143500068124|161|0|statement||DELETE FROM Point WHERE id = 'OmEWtzi9bM9etJISTKWWjKaUlmUTopM6c8W5xGQUN8yKp7HQFs' 1143500068206|1|0|rollback|| What I do not get is that the database foreign key check is deferrable (postgres), so this statement should be ok if followed by the deletion of the Area, but i have to look more precisely at the meaning of deferred in postgres. Anyway if it does not work i will try to reverse the relation and it should work. Thank you. Jean-Yves > Thank you. > > > > Jean-Yves > > > > P.S.: > > > > I'am not a foreign key constraint expert, but i tried to use > deferrable=true > > for this constraint and it does not work neither. > > strange! I would expect that in this case delete ordering is irrelevant. > > regards, > Armin > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
Re: auto delete and foreign keys
Hi Jean-Yves, Jean-Yves Sironneau wrote: Hello, Yes another question again. I have a class Area that is referencing a class Point, and Area has a foreign key constraint on Point. I'am using ODMG, and i would like OJB to delete the Point when i delete the Area. What happens is that when i commit a transaction for removing an Area, OJB is trying to remove the Point but of course it can't because the foreing key constraint is violated as the Area is still referencing the point. So i suppose the Area should be removed first for this to work. Do you think it can be a bug ? Do i have to manually unreference the point somewhere ? Do you use auto-delete="object" in Area 1:1 reference-descriptor to Point? http://db.apache.org/ojb/docu/guides/odmg-guide.html#Specific+Metadata+Settings If you have problems with the order of persistent objects you can A. disable ordering and set object order by hand (first delete Area, then Point) http://db.apache.org/ojb/docu/guides/odmg-guide.html#Disable+OJB%27s+object+ordering%2C+determine+object+order+%22by+hand%22 B. use a workaround to specify the database FK. Simply set a custom property 'constraint' in reference-descriptor of Area. http://db.apache.org/ojb/docu/guides/odmg-guide.html#Foreign+Keys+Constraints+and+ODMG-api If set OJB's ordering try to take care of the database constraint. Thank you. Jean-Yves P.S.: I'am not a foreign key constraint expert, but i tried to use deferrable=true for this constraint and it does not work neither. strange! I would expect that in this case delete ordering is irrelevant. regards, Armin - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
