Transparent Timestamp fields

[ryanramage]

I am currently working to add temporal support to the underlying database. For all my entity beans I require some timestamp fields. I want these fields to be transparent to the application. Each update to the underlying db will result in this timestamp being changed. For example: each bean will have a validStart and validEnd timestamp.
A current valid entry will have a validEnd timestamp as NULL.

This affects the persistance SQL code. When a bean loads it will be changed from

select * from Bean where id = primaryKey;
to
select * from Bean where id = primaryKey and validEnd is null;

Deleting a bean will changed from
delete from Bean where id = primary key
to
update Bean set validEnd = NOW() where id = primaryKey and validEnd is null; insert into Bean values(primaryKey,...,Now(), NULL);

Same deal with updates and select. Hope you get the picture.

Now I dont want to create fields in my bean as a timestamp (as I want it transparent). So I have to add something to the ejb container. Where would I look to do this? Any suggestions? Is there a way I could alter the SQL by adding an interceptor to the call stack? Or do I have to just hard code the sql? Anyone done anything like this before?

[ryanramage]

I love JBoss! Looking at the source, it was not that hard to find out what to do. If anyone cares the steps are:

1) Extend each of the JDBCCommand classes (eg JDBCRemoveEntityCommand) and change the SQL where needed.

2) Create a subclass of org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager and as part of the Factory Pattern call each of the new classes from step 1.

3) change the persistence-manager in standardjboss.xml to the class in step 2.

Just that easy! =) Now just to make sure that my new sql does not mess anything up =)

[ryanramage]

I love JBoss! Looking at the source, it was not that hard to find out what to do. If anyone cares the steps are:

1) Extend each of the JDBCCommand classes (eg JDBCRemoveEntityCommand) and change the SQL where needed.

2) Create a subclass of org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager and as part of the Factory Pattern call each of the new classes from step 1.

3) change the persistence-manager in standardjboss.xml to the class in step 2.

[ryanramage]

I love JBoss! Looking at the source, it was not that hard to find out what to do. If anyone cares the steps are:

1) Extend each of the JDBCCommand classes (eg JDBCRemoveEntityCommand) and change the SQL where needed.

2) Create a subclass of org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager and as part of the Factory Pattern call each of the new classes from step 1.

3) change the persistence-manager in standardjboss.xml to the class in step 2.