在JPQL中进行转换时出错

Question

这是在JSF + JPA Web应用程序上。

当我使用包含强制转换的以下JPQL查询时，它会给出一个难以理解的错误。

这是查询

jpql = "select new data.dataStructure.PharmacyStockRow(amp.vmp.name, sum(s.stock), "
+ "sum(s.itemBatch.purcahseRate * s.stock), sum(s.itemBatch.retailsaleRate * s.stock))"
+ "from Stock s join treat(s.itemBatch.item as Amp)amp "
+ "where s.stock>:z and s.department=:d "
+ "group by amp.vmp ";
m.put("d", department);
m.put("z", 0.0);

这是为了从查询中接收结果而创建的类。

package data.dataStructure;

public class PharmacyStockRow {
   String code;
   String name;
   Double qty;
   Double purchaseValue;
   Double saleValue;

   public PharmacyStockRow() {
   }

   public PharmacyStockRow(String name, Double qty, Double purchaseValue, Double saleValue) {
       this.name = name;
       this.qty = qty;
       this.purchaseValue = purchaseValue;
       this.saleValue = saleValue;
   }

我有一个Stock类，用于存储有关股票的数据。它有一个表示批处理的ItemBatch类。批处理有一个项目。那个项目实际上是一个Amp，它扩展了Item。 Amp有一个Vmp。我想通过Vmp获得股票。如果ItemBatch具有Amp的属性，那将非常容易，但我不得不使用更通用的Item作为参考。所以我需要在Java Resistance Query中将Item转换为Amp。我尝试了但是它出现了以下错误。

我使用EclipseLink 2.5作为持久性提供者。

Caused by: Exception [EclipseLink-6034] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.QueryException
Exception Description: Invalid query item expression [
Query Key vmp
   Query Key item (entity.pharmacy.Amp) 
      Query Key itemBatch
         Base entity.pharmacy.Stock].
Query: ReportQuery(referenceClass=Stock jpql="select new data.dataStructure.PharmacyStockRow(amp.vmp.name, sum(s.stock), sum(s.itemBatch.purcahseRate * s.stock), sum(s.itemBatch.retailsaleRate * s.stock))  from Stock s join treat(s.itemBatch.item as Amp)amp where s.stock>:z and s.department=:d group by amp ")
    at org.eclipse.persistence.exceptions.QueryException.invalidExpressionForQueryItem(QueryException.java:622)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.getLeafDescriptorFor(ObjectLevelReadQuery.java:1460)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.getLeafMappingFor(ObjectLevelReadQuery.java:1408)
    at org.eclipse.persistence.internal.queries.ReportItem.initialize(ReportItem.java:124)
    at org.eclipse.persistence.queries.ConstructorReportItem.initialize(ConstructorReportItem.java:137)
    at org.eclipse.persistence.queries.ReportQuery.prepare(ReportQuery.java:1044)
    at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:613)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.checkPrepare(ObjectLevelReadQuery.java:823)
    at org.eclipse.persistence.queries.DatabaseQuery.prepareCall(DatabaseQuery.java:1741)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:268)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:190)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:142)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:126)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.createQuery(EntityManagerImpl.java:1475)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.createQuery(EntityManagerImpl.java:1497)

Answer 1

我没有解决这个问题，但做了一个解决方案。我将子类中的所有其他方法添加到父类中，以便不需要进行转换。