[nhibernate-issues] [JIRA] Updated: (NH-1090) Query cache does not work when using Criteria API to create a projection query with a result transformer

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

     [ http://jira.nhibernate.org/browse/NH-1090?page=3Dcom.atlassian.jira.=
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Sergey Koshcheyev updated NH-1090:
----------------------------------

    Fix Version/s:     (was: 1.2.1)
                   LATER

> Query cache does not work when using Criteria API to create a projection =
query with a result transformer
> -------------------------------------------------------------------------=
-------------------------------
>
>                 Key: NH-1090
>                 URL: http://jira.nhibernate.org/browse/NH-1090
>             Project: NHibernate
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 1.2.0.GA
>            Reporter: Olli Ryh=C3=A4nen
>            Priority: Major
>             Fix For: LATER
>
>
> Enabling query-cache on a projection query with a result transformer atta=
ched using Criteria API, will fail with an exception:
> "System.InvalidCastException: Unable to cast object of type '<The output =
type from the result transformer' to type 'System.Object[]'"
> The exception is caused by the line:
> "cacheable.Add( TypeFactory.Disassemble( ( object[ ] ) result[ i ], retur=
nTypes, session ) );"
> in "NHibernate\Cache\StandardQueryCache.cs" on line 63, when it tries to =
cast the "result[i]" to an "object[]".
> Using result transformers the result set has already been transformed to =
the transformed type, before adding to the cache, so casting to "object[]" =
will fail. (The transformation is done in the method "GetResultColumnOrRow"=
 in CriteriaLoader.cs on line 74, which gets called in process of loading t=
he result set from the database).
> To reproduce the issue, turn on caching on any of the projection query te=
sts with result transformer in "CriteriaQueryTests.cs". E.g. on line 494
> IList resultWithAliasedBean =3D s.CreateCriteria(typeof (Enrolment))
>    .CreateAlias("Student", "st")
>    .CreateAlias("Course", "co")
>    .SetProjection(Projections.ProjectionList()
>          .Add(Projections.Property("st.Name"), "studentName")
>          .Add(Projections.Property("co.Description"), "courseDescription"=
)
>    )
>    .AddOrder(Order.Desc("studentName"))
>    .SetResultTransformer(Transformers.AliasToBean(typeof (StudentDTO)))
>    .SetCacheable(true)
>    .List();
> A simple fix would be to check if the type of "result[i]" is an "object[]=
" before adding to the cache and cache non "object[]" types as is to the ca=
che (and do the same check when getting the items back from the cache), but=
 I'm not sure if that would break the caching architecture in some way.=20

--=20
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