[nhibernate-issues] [JIRA] Created: (NH-855) Lazy collection retrieval should use proxies

[NHibernate J. <mik...@us...>]

Lazy collection retrieval should use proxies
--------------------------------------------

         Key: NH-855
         URL: http://jira.nhibernate.org/browse/NH-855
     Project: NHibernate
        Type: Improvement
  Components: Core =20
    Versions: 1.2.0.Beta2   =20
    Reporter: Andr=C3=A9s G. Aragoneses
    Priority: Minor
 Attachments: NHibBugAboutDataRetrieval.zip

When retrieving a lazy collection I've noted that there is much information=
 retrieved from the DB that may not be needed. For example, if we only need=
 the Count property of the collection, NHibernate retrieves full objects in=
stead of just proxies (object with only the ID property filled).

I am attaching a testcase.

Note the folling C# lines in the testcase:

IList aParameters =3D oSession.CreateCriteria(typeof(Parameter)).List();

if (aParameters.Count =3D=3D 0)
{
    return;
}
Parameter oParameter =3D aParameters[0] as Parameter;

//the Group is a proxy object, so this instruction does not retrieve anythi=
ng from DB
int iIdGroup =3D oParameter.Group.Id;

//this instruction unproxies the object because it is filled with its prope=
rties
string sName =3D oParameter.Group.Name;

//why don't we retrieve here only proxies? because we only need to know how=
 many rows, their ID's
int iCount =3D oParameter.Group.Terminals.Count;

//if in the last instruction NHibernate would have retrieved proxies instea=
d of full objects
//this instruction would generate a new query
string sName2 =3D oParameter.Group.Terminals[0].Name;

I know that maybe this is a too specific feature and perhaps, to be impleme=
nted, it should be done so by adding a new configuration parameter, for exa=
mple: RetrievalMode.Minimal.

What do you think?

P.S.: You may add the NHib libs to the Lib subdir of the ZIP file attached,=
 before building it.

--=20
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