Eclipse Community Forums: EclipseLink » How to approach data tracking?

Home » Eclipse Projects » EclipseLink » How to approach data tracking?(So that updates to the database INSERT instead of UPDATE)

Show: Today's Messages :: Show Polls :: Message Navigator

How to approach data tracking? [message #522017]

Fri, 19 March 2010 16:14

Carlos Conti

Messages: 26
Registered: January 2010

Junior Member

Hi all,

I am newbie to JPA and have been developing an essay application for my organisation. Currently I am almost at the end of it, but there remains an issue regarding data tracking in the backend database.

Currently I have come to record data in a 'record per instance' manner. This model doesn't allow me to track changes in a userfriendly way. I can figure out tricky ways of doing it, if I must unavoidably stick to this way of doing things. However I am sure there must be an easier way to build it with another pk strategy.

I would like to adopt a double primarykey where in one field I would have my currently automatically created id (through an 'Identity' pk generation strategy), and in the second field I would have a DELETED flag such as {0,1}.

If possible I would appreciate if someone could give me a hint on how to get there.

Thanks in advance for your help!
Carlos.

Report message to a moderator

Re: How to approach data tracking? [message #522040 is a reply to message #522017]

Fri, 19 March 2010 13:34

Tom Eugelink

Messages: 817
Registered: July 2009

Senior Member

> This model doesn't allow me to track changes in a userfriendly way.

If your problem is solved by keeping a history of changes; Eclipselink supports storing old versions of a record in a separate history table, together with a valid from-until timestamp pair.

Tom

Report message to a moderator

Re: How to approach data tracking? [message #522050 is a reply to message #522040]

Fri, 19 March 2010 18:40

Carlos Conti

Messages: 26
Registered: January 2010

Junior Member

Cool!, but where do you specify that?

I am using the JPA Eclipse IDE to write the ORM file, and so far haven't seen any reference to what you're saying. Could you tell me in which context must I define that? entity context?, persistence context?, I presume entitycontext...

should I create a secondary table for that? and then how do I specify I want to add an old record...

thanks!
Carlos.

Report message to a moderator

Re: How to approach data tracking? [message #522085 is a reply to message #522050]

Fri, 19 March 2010 16:26

Tom Eugelink

Messages: 817
Registered: July 2009

Senior Member

On 2010-03-19 19:40, Carlos Conti wrote:
> Cool!, but where do you specify that?

http://wiki.eclipse.org/Configuring_a_Descriptor_(ELUG)#Conf iguring_a_History_Policy

> should I create a secondary table for that? and then how do I specify I
> want to add an old record...

The history table is an exact copy of the actual table plus two fields. A new record is added to the history table as soon as the original record is updated. Works like a charm for me.

Tom

Report message to a moderator