使用休眠条件选择值对象 [英] using hibernate criteria to select into value objects

问题描述

我正在尝试使用Hibernate Criteria API来执行以下HQL:

I'm trying to find out if it is possible to do the following HQL using the Hibernate Criteria API:

String hql = "select new InitialCount(substring(name, 1,1), count(id)) from Person group by substring(name, 1,1)";

InitialCount是一个非常简单的bean，具有字符串和长构造函数:

Where InitialCount is a very simple bean with a string and long contructor:

public static class InitialCount {
    private final String initial;
    private final long count;

    public InitialCount(String initial, long count) {
        this.initial = initial;
        this.count = count;
    }
}

有可能吗?

推荐答案

尝试一下:

criteria.setProjection(Projections.projectionList()
        .add(Projections.groupProperty("formulaProp").as("initial"))
        .add(Projections.count("id").as("count"))
            ).setResultTransformer(Transformers.aliasToBean(InitialCount.class)).list();        

---

其中FormulaProp是使用公式"substring(name，1,1)"映射的人员的属性

---

where formulaProp is a property of person mapped with the formula "substring(name, 1,1)"

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