users@jpa-spec.java.net

[jpa-spec users] [jsr338-experts] (Fwd) Proposal: Introduce _at_Query annotation for fields

From: Rainer Kwesi Schweigkoffer <kwesi_at_sap.com>
Date: Tue, 20 Dec 2011 16:38:23 +0100

Hi all,

how do you feel about Daniel Sachse's proposal on the observer list ?
Having talked to a couple of users I got the feedback that they'd
consider it a quite useful feature.

Precise name of the annotation would have to be discussed. I'd rather
expect standard JPQL syntax for the query string (selects only, of
course) or preferably names of named Queries. In the latter case one
might also dare to think of a load attribute for the @Transient
annotation. Support of fetch types would be helpful.

Comments ?

Best regards
Rainer

------- Weitergeleitete Nachricht / Forwarded message -------
Datum: Thu, 8 Dec 2011 11:06:09 +0100
Von: Daniel Sachse <sachsedaniel_at_googlemail.com>
An: users_at_jpa-spec.java.net
Betreff: [jpa-spec users] Proposal: Introduce @Query
annotation for fields
Antwort an: users_at_jpa-spec.java.net

Hello everyone,

I would like to propose a new feature for JPA. To make it more clear,
I will show you my use case:

I have got a customer object with a list of offers:

<code>

@OneToMany
private List<Order> orders;

</code>

So far, so good. As soon as I want a List with all undelivered
orders,
I have to create a separate business method, call the EntityManager
with a specific query and set the resultset in my POJO.
>From my point of view, this is overhead!
My proposal:

<code>

@Transient
@Query("FROM Order WHERE delivered = false")
private List<Order> undeliveredOrders;

</code>

But I don't want it only to apply for collections, but also for other
field types:

<code>

@Transient
@Query("FROM Order WHERE status = ? ORDER BY ", OrderStatus.Failed)
private Order lastFailedOrder;

</code>

Additionally a FetchType would be good to specify.

Regards,

Daniel

--- Ende der weitergeleiteten Nachricht / End of forwarded message ---
---
Rainer Schweigkoffer                      SAP AG Walldorf
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