在JPQL中选择NEW

Question

我遇到SELECT NEW查询的问题。

Query q = em.createQuery(
           "SELECT NEW com.bcbst.odstats.ejb.RangeStats(a.folderName, SUM(a.hits)) " +  
           "FROM ODStat a GROUP BY a.folderName");
return q.getResultList();

当我尝试运行此查询时，我收到以下 stacktrace 。 RangeStats 确实有公共方法，FQN是准确的，实际上RangeStats与该类位于同一个包中进行查询。我以前在ODStat上做过查询，所以我也相信a.folderName和a.hits是可以的。

我正在开发RAD 7.5，WAS 7，OpenJPA 1.2.1，MS SQL JDBC Driver 1.2。

    at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:896)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1527)
Caused by: javax.ejb.EJBException: See nested exception; nested exception is: 
<openjpa-1.2.1-SNAPSHOT-r422266:686069 nonfatal user error> 
org.apache.openjpa.persistence.ArgumentException: Result type "class 
com.bcbst.odstats.ejb.RangeStats" does not have any public fields or setter methods 
for the projection or aggregate result element "jpqlalias1", nor does it have a 
generic put(Object,Object) method that can be used, nor does it have a public 
constructor that takes the types [class java.lang.String, long].

Caused by: <openjpa-1.2.1-SNAPSHOT-r422266:686069 nonfatal user error> 
org.apache.openjpa.persistence.ArgumentException: Result type "class 
com.bcbst.odstats.ejb.RangeStats" does not have any public fields or setter methods 
for the projection or aggregate result element "jpqlalias1", nor does it have a 
generic put(Object,Object) method that can be used, nor does it have a public 
constructor that takes the types [class java.lang.String, long].

at org.apache.openjpa.kernel.ResultPacker.<init>(ResultPacker.java:139)
at org.apache.openjpa.kernel.ResultPacker.<init>(ResultPacker.java:102)
at org.apache.openjpa.kernel.QueryImpl.getResultPacker(QueryImpl.java:1262)
at org.apache.openjpa.kernel.QueryImpl.toResult(QueryImpl.java:1212)
at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:990)
at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:805)

Answer 1

发现问题。 构造函数在需要(String, int)时接受(String, long)。

Answer 2

跟我来

 public Company(String name, int iva, String businessArea, String coreBusiness) {
    this.name = name;
    this.iva = iva;
    this.businessArea = businessArea;
    this.coreBusiness = coreBusiness;
    }

Query query = session.createQuery("select new Company (name, iva, businessArea, coreBusiness)  from Company");


obs : org hibernate