[jboss-user] [EJB 3.0] - Database triggers

[jbeer]

Hi,

I am storing a heirarchical structure in the database using left and right traversal values.  Every time I insert a record into a table, I have a after-insert trigger than fires and updates many records in this table (a number of rows left and right traversal values can change when inserting a new record).

This works fine.  Enter EJB3.  Now this doesn't work fine:  When I persist an entity that affects mutliple rows in the database, I need to refresh all of the entities that were affected by the after-insert trigger in the database.  I don't know the exact entities that will be affected, so it seems like clearing the entity manager might be a good way (albeit expensive) to accomplish this.  Entity callbacks seemed like the way to approach this, using @PostPersist annotation on the entities that get updated.  However, I can't seem to get a hold of the EntityManager (through the bean, injection, or a JNDI lookup).

a) Can you get an EntityManager from an entity callback?

b) Is there a better approach to do this?  I have thought of moving the database triggers into java code in the Entity callback, but since I can't get the EntityManager at this point, that's not a viable option.

Any thoughts and help is appreciated,
Jonathan

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