Hibernate：标准中多对一的投影

发布于 2024-08-07 10:06:10 字数 554 浏览 5 评论 0原文

我最近第一次使用 hibernate Criteria API。

我试图做相当于此 HQL

“从任务 t 选择 t.userTbl”

userTbl 属性是来自任务的多对一。 Task.userTbl 关系是惰性的。

所以我想出了这个，

Criteria criteria = session.createCriteria( Task.class, "t" );
criteria.setProjection( Projections.property( "t.userTbl" ) );
List results = criteria.list();

不幸的是，这与 HQL 做了一些不同的事情。

在 HQL 中，尽管 userTbl 关系在映射中设置为惰性，但 HQL 会急切地获取并具体化 UserTbl 的非代理对象。

然而，在标准中，我得到了我不想要的代理列表。我摆弄了 setFetchMode 但这似乎不是正确的事情。任何人都知道如何在标准中正确执行上述操作并像 HQL 一样恢复非代理？

谢谢。

原文

I am playing around with the hibernate Criteria API for the first time recently.

I was trying to do the equivalent of this HQL

"select t.userTbl from Task t"

userTbl property is a many-to-one from Task. The Task.userTbl relationship is lazy.

So I came up with this

Criteria criteria = session.createCriteria( Task.class, "t" );
criteria.setProjection( Projections.property( "t.userTbl" ) );
List results = criteria.list();

Unfortunately this does something different to HQL.

In HQL although the userTbl relationship is set to lazy in the mapping the HQL eagerly fetches and materialises non-proxy objects of UserTbl.

However in the Criteria I get a list of proxies back which I don't want. I fiddled around with setFetchMode but this didn't seem to be the right thing. Anyone have any idea how to do the above in a Criteria properly and get non-proxies back like HQL?

Thanks.

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