我遇到了 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, 我得到以下堆栈跟踪。RangeStats确实有公共方法,FQN 是准确的,实际上 RangeStats 与进行查询的类位于同一个包中。我之前对 ODStat 进行过查询,所以我也确信 a.folderName 和 a.hits 是可以的。
我正在使用 RAD 7.5、WAS 7、OpenJPA 1.2.1、MS SQL JDBC Driver 1.2 进行开发。
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)