Hi List,


I would like to avoid lazy loading in my application depending on the context.
Here is my object graph :

A
AA
AAA AAB AAC

All relations are one-to-many (A contains may AA which contains many AAA AAB and AAC)

A child collections are mapped "lazy", because in most cases this is the intended behavior.
However in one case I would like to fetch all AAA - AAB and AAC objects without lazy loading.

Is there a way to do this with HQL ?

I've tried this by writing a query loading all AAA's and then left join fetch to its parents (AA - A), and then load all AAB's, which works correctly. But when I start looping the AA.AAB collection I see that the queries to fetch the AAB's are executed again although the objects are already in my session.

Any ideas ?

Use the fetch keword. It doesn't have to be a left join as it is in my example.

from A
left join fetch a.aa

When using Criteria use Criteria.SetFetchMode(FetchMode.Eager)

-Cole

This does not work.
It only works for ONE collection.
I could use it to get AA.AAA but not to get AA.BBB and AA.CCC


Thanks for the proposal.

Yes, that is the same problem I just posted when I saw yours. You cannot preload two associations because it would create a cartesian product (if using left outer joins). This is explicitly prohibited by NHibernate.

What might possibly work is setting the mapping to fetch="select". I might try that and see.

A two-fer! http://www.hibernate.org/hib_docs/nhibernate/1.2/reference/en/html/performance.html#performance-multi-query, near the bottom.

Version 1.20 GA does not have UniqueResult. Also, what if I want to load a list of items that has two collections loaded? Could i use List?...

Thanks a lot.
I had no time to try out this solution jet, but I will certainly due so in the comming days !

I'll keep you posted if it works out well, looks good !

SEEMS TO WORK !

Instead of 80 seconds (by use of lazy loading) I get the data in 12 seconds !
And indeed the UniqueResult is not available but it works with the list as well.

Thanks for the proposal !!!!

Hi, I have your same problem, what does it mean: "the UniqueResult is not available but it works with the list ".

Thank in advance
Giorgio