[Hibernate] type safe criteria queries

[Dhananjay P. <dpr...@em...>]

Hi I am sending this again could anyone tell me if this might be useful
to the communitY? I would like to help if it would be.

Thanks,

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Dhanji,

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________________________________

From: hib...@li...
[mailto:hib...@li...] On Behalf Of
Dhananjay Prasanna
Sent: Wednesday, 28 June 2006 11:31 AM
To: hib...@li...
Subject: [Hibernate] (semi) Entity-type safe criteria queries

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Hi All

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I am writing to ask about type-safety (in a very rudimentary way) in
Criteria queries. I know there has been some discussion around this
topic with the SODA group and others, but I am curious if this has been
considered for Hibernate.

Basically, instead of using the system:

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Criteria q =3D session.createCriteriaQuery(MyClass.class);

q.add ( Restriction.eq( "propName", value) );

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which is unsafe to the entity-type under query, would it be possible to
do something like:

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Criteria q =3D session.createSafeCriteriaQuery(MyClass.class);

MyClass my =3D q.obtainQueryable(MyClass.class);

q.add( Restriction.eq( my.getPropName(), value ));

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The special instance "my" would contain proxies or bytecode-instrumented
properties that would return the appropriate mapped property name to the
Criterion. Apart from being safe to the Entity type under consideration
(statically) and its properties, this approach has the added advantage
of bringing criteria queries into an IDE's refactoring scope.

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The cons are the added performance hit of proxies or bytecode
manipulation, and the extra step in obtaining a reference to a queryable
entity. However I believe the pros far outweigh this, as my own project
occasionally undergoes property-refactoring and has a LOT of
similarly-named properties across classes (too many for a sane person to
discriminate on sight!).

Anyway, I thought I would bring it up-Im sure typesafety has been
discussed before so please forgive me if this is a rehash. I'm also
happy to contribute an implementation of this if you guys find it worth
adding.

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Thanks!!

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Dhanji.

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This correspondence is for the named persons only.=0D
It may contain confidential or privileged information or both.=0D
No confidentiality or privilege is waived or lost by any mis transmission.=
=0D
If you receive this correspondence in error please delete it from your=
 system immediately and notify the sender.=0D
You must not disclose, copy or relay on any part of this correspondence, if=
 you are not the intended recipient.=0D
Any opinions expressed in this message are those of the individual sender=
 except where the sender expressly,=0D
and with the authority, states them to be the opinions of the Department of=
 Emergency Services, Queensland.