從javax.persistence.Query構建org.eclipse.persistence.queries.ReportQuery

Question

我正在嘗試使用單個命名查詢來獲取一組結果並計算可用數據量。 我有一個命名的JPQL查詢：

@NamedQuery(name = "query.all.absences.by.name", query = "SELECT a FROM Absence a WHERE a.name = :name") 

當我獲得缺勤時，我將像這樣調用查詢：

final Query q = em.createNamedQuery("query.all.absences.by.name");
q.setParameter("name","aRandomAbsenceName");
//maxResults and firstResult are coming as parameters, are computed in another method
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);

q.getResultList()我提供了正確的結果集。 到現在為止還挺好。

現在，我要做的是使用相同的命名查詢來執行計數查詢。 我正在執行以下操作：

final Query q = em.createNamedQuery("query.all.absences.by.name");
q.setParameter("name","aRandomAbsenceName");
q.setHint(QueryHints.QUERY_TYPE, "org.eclipse.persistence.queries.ReportQuery");
final ReportQuery test = JpaHelper.getReportQuery(q);
test.addCount();
test.setShouldReturnWithoutReportQueryResult(true);

如果我的命名查詢沒有參數，則此方法效果很好。 但是使用參數時，如果執行上面定義的ReportQuery，則將出現以下異常：

Exception [EclipseLink-6094] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.QueryException
Exception Description: The parameter name [name] in the query's selection criteria does not match any parameter name defined in the query.
Query: ReportQuery(referenceClass=AbsenceCategory sql="SELECT COUNT(CATEGORY_KEY) FROM ABSENCE_CATEGORY WHERE (CATEGORY_KEY = ?)")
    at org.eclipse.persistence.exceptions.QueryException.parameterNameMismatch(QueryException.java:1063)
    at org.eclipse.persistence.internal.expressions.ParameterExpression.getValue(ParameterExpression.java:275)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseCall.translate(DatabaseCall.java:1000)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:206)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:193)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelectCall(DatasourceCallQueryMechanism.java:264)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.selectAllRows(DatasourceCallQueryMechanism.java:646)
    at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRowsFromTable(ExpressionQueryMechanism.java:2611)
    at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllReportQueryRows(ExpressionQueryMechanism.java:2554)
    at org.eclipse.persistence.queries.ReportQuery.executeDatabaseQuery(ReportQuery.java:846)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:844)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1040)
    at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:392)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1128)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2871)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1516)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1498)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1449)

我還能如何將參數設置為ReportQuery？

我正在使用EclipseLink 2.0。

Answer 1

您如何執行ReportQuery？ 您需要調用Session.executeQuery（query，arguments）並傳遞參數列表（順序與query.getArguments（）相同）。

您可能還可以使用JpaEntityManager createQuery（DatabaseQuery）API將ReportQuery轉換回JPA查詢，然后可以通過JPA方式設置參數。