Load all lazy properties at once

Simon_Says · **Joined:** Fri Apr 27, 2007 11:41 am **Posts:** 9

hi @ all
i wonder if there is a function to load all lazy properties of an object at once. right now i iterate with reflection through all properties and initialize each of them seperate, but that is quite time consuming. is there a better way?

greez simon

ps: i am using NHibernate 1.2.0

jnapier · **Joined:** Sat Sep 10, 2005 3:46 pm **Posts:** 178

lazy="false" in the mapping

Simon_Says · **Joined:** Fri Apr 27, 2007 11:41 am **Posts:** 9

yes sure, but that is not really what i want. i do not want to load all the properties every time i load the object.
i load a list of objects and display them in a list. if the user chooses one of them, then i like to load all its lazy properties. not of all object in the list!

luedi · **Joined:** Tue Feb 21, 2006 9:50 am **Posts:** 107

normally we use views to display lists of data. The view contains the primary key of the detail data. If the user selects a line the detail data will be read via the primary key. The view contains only the nessecary data. If the data has to be read via joins from multiple tables these joins are precompiled and processed on the database server which reduces the traffic between the client and the server. You can map views like tables with NHibernate.

Regards
Klaus

xasp · **Posted:** Sun Apr 29, 2007 6:07 am

Hello,

I didn't test it, but wouldn't NHibernateUtil.Initialize(<object>) do this ?
You'll have to Lock() or Refresh() your object prior to doing this, of course.

Simon_Says · **Joined:** Fri Apr 27, 2007 11:41 am **Posts:** 9

no, unfortunately that does not work :-(

@ luedi: yes that would probably be the most preferred solution, but i need all the objects before... don't ask why! :-)

adamgibbons · **Joined:** Sat Apr 21, 2007 11:01 pm **Posts:** 144

How about using eager fetching?
There is a breif point on it in the "best practices" section of the hibernate docs, although it does say not to do it. lol :P

Quote:

Prefer lazy fetching for associations.
Use eager (outer-join) fetching sparingly. Use proxies and/or lazy collections for most associations to classes that are not cached at the JVM-level. For associations to cached classes, where there is a high probability of a cache hit, explicitly disable eager fetching using outer-join="false". When an outer-join fetch is appropriate to a particular use case, use a query with a left join fetch.

http://www.hibernate.org/hib_docs/refer ... tices.html

jnapier · **Joined:** Sat Sep 10, 2005 3:46 pm **Posts:** 178

if you want to override the fetching specified in the mapping files then use a fetch join

Code:

from Eg.Cat as cat 
    inner join fetch cat.Mate
    left join fetch cat.Kittens

or specify the fetch group through the criteria api

Code:

IList cats = sess.CreateCriteria(typeof(Cat))
    .Add( Expression.Like("Name", "Fritz%") )
    .SetFetchMode("Mate", FetchMode.Eager)
    .SetFetchMode("Kittens", FetchMode.Eager)
    .List();

of course all this is in the docs.

Simon_Says · **Joined:** Fri Apr 27, 2007 11:41 am **Posts:** 9

thanks a lot! eager was a good hint. i still iterate with reflection through all properties, but now i can load them all at once.

greez simon

jnapier · **Joined:** Sat Sep 10, 2005 3:46 pm **Posts:** 178

not sure what you are using relfection for on your properties but you can check if a lazy loaded assosciation is initialiazed ot not with

Code:

NHibernateUtil.IsInitialized