Hello all,

Does possible use the hibernate (and NHibernate) for only to generate SQL statements for changed objects !? I don't want that the Hibernate/NHibernate send statements for the SGDB.
If this is possible, how I get this statements's?!

Thank's...
FernandoVM

Anybody know!? :(

I'm not sure if this is what you are looking for, but use the following definitions on your persistent classes:


Fields that have a value only will appear in the Insert statement



Only fields that have changes will be included in the Update statement


If you are hoping NHibernate will be able to inspect each of your objects and know which one has changed state since it was read from the DB, it doesn't do that to the best of my knowledge.

Hope this helps.

eh, that is exactly what it does ;)


How else could e.g. dynamic-insert and dynamic-update work?

Hi,

Thank's by attention... Well, in reality isn't this that I want. I want that the NHibernate don't establish a connection to a database for submit SQL statements, I want that it only generate this statements for I after submit it manually.

[]'s
FernandoVM

so write a wrapper around a jdbc driver and collect the statements for you to execute later.

Actually, I thought he was asking if NHibernate kept track of the objects that were changed as you were changing them. You still need to initiate the SaveOrUpdate method for each object you change.

TOPLink for Java does it a little differenctly. It keeps track of the objects you change as you change them within your session cache. That is, the developer only needs to register his object(s) into his UnitOfWork make any change to these objects and then says commit. TOPLINK then inspects each object to see which ones have changed and then generates the dynamic SQL for the changes as required.

eh, yes! But that is still how Hibernate (and nhibernate) works.

/max

unitofwork = (more or less) Session

This was the first thing in the wich I think, but I want know if thre are a way less intrusive... :)

Thank's by attention!

[]'s
FernandoVM

Actually, You do not need to. The SaveOrUpdate is needed only if the object is obtained trought the different session. Inside one session, only new objects must be Save()-d.

Gert

Thanks guys. I didn't realize NHibernate did this within a single session. I like it even more now!

Greg

...and that is not even needed if they are reachable over an cascadable association from an existing persistent object.

I can't use directally the Hibernate O/R mapping class to only generate SQL statements without use the hibernate background (session, transactions e etc...) ?? This wold be very usefull to me... :)

[]'s
FernandoVM

eh what is so bad about using those api's to get it with ? :)