如何在Hibernate Criteria中添加Distinct [英] How to add Distinct in Hibernate Criteria

问题描述

在我的数据库中，我有一个测试表，列：testName，testType
有两个不同的测试，具有相同的类型即SUN，所以我只想要其中的一个我在其中使用Distinct hibernate / criteria如下，但它仍然给我两个与sun同名的类型。

In my database I have a Test table, with columns: testName, testType there are 2 different tests with the same type I.e "SUN", so I want only one of them for which I use Distinct in my hibernate / criteria as below, but it still giving me both the types with the same name as "sun".

        Criteria crit = session.createCriteria(Test.class);

    final ResultTransformer trans = new DistinctRootEntityResultTransformer();
    crit.setResultTransformer(trans);
    List rsList = trans.transformList(crit.list());

任何想法可能是什么原因，或任何其他方式过滤重复。

Any idea what could be the reason, or any other way of filtering duplicates.

推荐答案

使用Projections.distinct。

Use Projections.distinct.

Criteria crit = session.createCriteria(Test.class).setProjection(
    Projections.distinct(Projections.projectionList()
    .add(Projections.property("type"), "type") )
.setResultTransformer(Transformers.aliasToBean(YourBean.class)); 

List lst = crit.list();

其中YourBean.class有一个属性type。返回的列表将是 List< YourBean> 。

where YourBean.class has a property "type". The returned list will be List<YourBean>.

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