如何使用jpa和hibernate将本机查询映射到POJO类 [英] How to map a native query to POJO class using jpa and hibernate

问题描述

我在我的项目中使用JPA和hibernate。

I am using both JPA and hibernate in my project.

我创建了一个查询，其中我在许多表上进行了连接操作。所以我创建了一个原生的。我得到的结果是在object []的列表中，但我希望将结果自动转换为java POJO类。
你可以查看下面的查询语法和POJO java类。

I have created a query in which i made join operation on many tables. So I created a native one. The results that i get are in a list of object[] but i would like the results to be converted automatically to a java POJO class. You can check both the query syntax and POJO java class below.

JPA查询

@Query(value = "SELECT obsp.Identifier, obs.phenomenontimestart, nv.value " +
        "From Series s " +
        "INNER JOIN Featureofinterest fi on s.featureofinterestid = fi.featureofinterestid " +
        "INNER JOIN ObservableProperty obsp on s.observablepropertyid = obsp.ObservablePropertyId " +
        "INNER JOIN Observation obs on s.seriesid = obs.seriesid " +
        "INNER JOIN NumericValue nv on nv.observationid = obs.observationid " +
        "where fi.identifier = ?1 and obs.phenomenontimestart >= ?2 AND obs.phenomenontimestart <= ?3 " +
        "order by obs.phenomenontimestart",
        nativeQuery = true)
List<CurrentMeasure> findCurrentMeasure(String ident, Timestamp t1, Timestamp t2);

POJO类

public class CurrentMeasure {

private String identifier;
private Timestamp dateTime;
private BigDecimal bigDecimal;

public CurrentMeasure() {
}

public CurrentMeasure(String identifier, Timestamp dateTime, BigDecimal bigDecimal) {
    this.identifier = identifier;
    this.dateTime = dateTime;
    this.bigDecimal = bigDecimal;
}

public String getIdentifier() {
    return identifier;
}

public void setIdentifier(String identifier) {
    this.identifier = identifier;
}

public Timestamp getDateTime() {
    return dateTime;
}

public void setDateTime(Timestamp dateTime) {
    this.dateTime = dateTime;
}

public BigDecimal getBigDecimal() {
    return bigDecimal;
}

public void setBigDecimal(BigDecimal bigDecimal) {
    this.bigDecimal = bigDecimal;
}

}

推荐答案

使用JPA，您可以直接在HQL查询中调用类 CurrentMeasure 的构造函数。

With JPA you can call the constructor of your class CurrentMeasure directly inside your HQL query.

示例：

SELECT NEW< package> .CurrentMeasure（obsp.Identifier，obs.phenomenontimestart，nv.value）FROM ...


Jboss文档在第11.5章。

另一个解决方案是使用 HQL变形金刚实现相同的结果没有求助于构造函数。

Another solution would be using HQL Transformers to achieve the same result without resorting to a constructor.

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