Question

我通过尝试使用SQL SERVER 2008数据库执行本机查询来解决JPA的问题。我真的不明白发生了什么。当我直接在数据库中执行查询时，我得到了以下结果（这是我所期待的）：

DS  Node    Total   MinDate     MaxDate
EMM CCND    7796    2013-04-16  2013-04-22
EMM CCNV    12049   2013-04-16  2013-04-22
EMM CGSN    1252    2013-04-16  2013-04-22
EMM MSC     7456    2013-04-16  2013-04-22
EMM SMSC    3999    2013-04-16  2013-04-22

但是在代码中，当我从EntityManager中检索数据时结果不一样。我得到的是以下内容：

DS  Node    Total   MinDate     MaxDate
EMM CCND    7796    2013-04-16  2013-04-22
EMM CCND    7796    2013-04-16  2013-04-22
EMM CCND    7796    2013-04-16  2013-04-22
EMM CCND    7796    2013-04-16  2013-04-22
EMM CCND    7796    2013-04-16  2013-04-22

我在同一行得到了相同的结果。很奇怪... 请有人帮我理解是什么问题。我怀疑PrimeFaces subtable组件，不能显示良好的数据，但现在我确信问题来自JPA Native Query。请参阅下面我正在使用的查询：

"select distinct DownStream.IDDownStream as DownStream, PortailMediation.IDNoeudOrigineCDR as Node, COUNT(CDR.NomSortie) as TotalFiles," + 
" MIN(convert(varchar(19),DateCDR,120)) as MinDate, MAX(convert(varchar(19),DateCDR,120)) as MaxDate" + 
" from DownStream, CDR, Equipement, PortailMediation" + 
" where DownStream.IDDownStream = Equipement.IDDownStream" +
" and PortailMediation.IDEquipement = Equipement.IDEquipement" + 
" and CDR.IDPortailMediation = PortailMediation.IDPortailMediation" +
" and DownStream.Nom = '" + downStream + 
"' and convert(varchar(10),DateCDR,103) between '" +  beginStr + "' and '" + endStr +
"' group by DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR" +
" order by DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR";

见下面的查询代码：

public class QueryManager {    
    private SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
    private String beginStr;
    private String endStr;

    /**
     * 
     * @param beginDate
     * @param endDate
     * @return 
     */
    public String getGroupedQuery(Date beginDate, Date endDate){        
        beginStr = sdf.format(beginDate);
        endStr = sdf.format(endDate);
        String groupedQuery = "select DownStream.IDDownStream as DownStream, PortailMediation.IDNoeudOrigineCDR as Node, COUNT(CDR.NomSortie) as TotalFiles," + 
                              " MIN(convert(varchar(19),DateCDR,120)) as MinDate, MAX(convert(varchar(19),DateCDR,120)) as MaxDate" + 
                              " from DownStream, CDR, Equipement, PortailMediation" + 
                              " where DownStream.IDDownStream = Equipement.IDDownStream" +
                              " and PortailMediation.IDEquipement = Equipement.IDEquipement" + 
                              " and CDR.IDPortailMediation = PortailMediation.IDPortailMediation" + 
                              " and convert(varchar(10),DateCDR,103) between '" +  beginStr + "' and '" + endStr +
                              "' group by DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR" +
                              " order by DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR"; 

        return groupedQuery;                     
    }

    /**
     * 
     * @param beginDate
     * @param endDate
     * @param downStream
     * @return 
     */
    public String getGroupedQueryByDownStream(Date beginDate, Date endDate, String downStream) {
        beginStr = sdf.format(beginDate);
        endStr = sdf.format(endDate);
        String groupedQuery = "SELECT DownStream.IDDownStream AS DownStream, PortailMediation.IDNoeudOrigineCDR AS Node, COUNT(CDR.NomSortie) AS TotalFiles," + 
                              " MIN(convert(varchar(19),DateCDR,120)) AS MinDate, MAX(convert(varchar(19),DateCDR,120)) AS MaxDate" + 
                              " FROM DownStream, CDR, Equipement, PortailMediation" + 
                              " WHERE DownStream.IDDownStream = Equipement.IDDownStream" +
                              " AND PortailMediation.IDEquipement = Equipement.IDEquipement" + 
                              " AND CDR.IDPortailMediation = PortailMediation.IDPortailMediation" +
                              " AND DownStream.Nom = '" + downStream + 
                              "' AND convert(varchar(10),DateCDR,103) BETWEEN '" +  beginStr + "' AND '" + endStr +
                              "' GROUP BY DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR" +
                              " ORDER BY DownStream.IDDownStream, PortailMediation.IDNoeudOrigineCDR"; 

        return groupedQuery;      
    }
}

调用List的EJB代码：

import java.util.Date;
import java.util.List;
import javax.ejb.Stateless;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import tg.moov.imereport.dao.DownStreamTotal;
import tg.moov.imereport.util.QueryManager;


@Named
@Stateless
public class DownStreamTotalEJB {

    @PersistenceContext
    private EntityManager em; 
    private QueryManager qm = new QueryManager();

    public DownStreamTotalEJB() {

    }

    /**
     * Get the grouped files by period
     * @param begin
     * @param end
     * @return 
     */
    public List<DownStreamTotal> getGroupedData(Date begin, Date end) {        
        Query q = em.createNativeQuery(qm.getGroupedQuery(begin, end), DownStreamTotal.class);        
        return q.getResultList();
    }

    /**
     * Get the grouped files by period and by downStream
     * @param begin
     * @param end
     * @param downStream
     * @return 
     */
    public List<DownStreamTotal> getGroupedDataByDownStream(Date begin, Date end, String downStream) {        
        Query q = em.createNativeQuery(qm.getGroupedQueryByDownStream(begin, end, downStream), DownStreamTotal.class);
        return q.getResultList();       
    }
}

EJB调用查询管理器以使查询执行。

提前谢谢！

Answer 1

最后我放弃了JPA，我使用JDBC直接连接Glassfish JNDI，它运行正常。谢谢！

Answer 2

在SQL SERVER 2008中使用Eclipselink时遇到了同样的问题。

使用createNativeQuery(queryString, targetEntity)创建查询后，似乎只能使用.getSingleResult()，但不能使用.getResultList()。它返回第一个实体的N倍。

我担心目前唯一的出路是使用List<Object[]>将数据检索为createNativeQuery(queryString)并手动执行映射。

JPA本机查询问题

2 个答案: