Re: [eclipselink-users] NEW() operation in JPQL query does not locate th

[James Sutherland <jamesssss@xxxxxxxxx>]

The NEW() function assumes the type on the constructor matches exactly the
returned values.

But I agree, it should be smart enough to find the constructor.  We should
search all constructors that match the number of arguments and find the best
match if an exact match is not find.  Please log a bug for this.



Pinaki Poddar wrote:
> 
> Hi,
>   NEW() operation in JPQL query does not locate the constructor correctly
> when generics are used.
> 
> Here is JPQL query using a NEW() operator
>         "select new openbook.util.Range(MIN(b.price), MAX(b.price)) from
> Book b";
> 
> where openbook.util.Range has the following constructor
>   public class Range<N extends Number>
>       public Range(N min, N max)
> 
> And Book.price is declared as
>       private double price;
> 
> 
> ends up with following stacktrace. Works if Range declares a constructor
> with two Object type arguments (and an ugly cast:)
>  
>      [java] Exception [EclipseLink-6137] (Eclipse Persistence Services -
> 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.QueryException
>      [java] Exception Description: An Exception was thrown while executing
> a ReportQuery with a constructor expression:
> java.lang.NoSuchMethodException: openbook.util.Range.<init>(
> java.lang.Object, java.lang.Object)
>      [java] Query: ReportQuery(referenceClass=Book jpql="select new
> openbook.util.Range(MIN(b.price), MAX(b.price)) from Book b")
>      [java]     at
> org.eclipse.persistence.exceptions.QueryException.exceptionWhileUsingConstructorExpression(QueryException.java:472)
>      [java]     at
> org.eclipse.persistence.queries.ConstructorReportItem.initialize(ConstructorReportItem.java:187)
>      [java]     at
> org.eclipse.persistence.queries.ReportQuery.prepare(ReportQuery.java:1026)
>      [java]     at
> org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:464)
>      [java]     at
> org.eclipse.persistence.queries.ObjectLevelReadQuery.checkPrepare(ObjectLevelReadQuery.java:732)
>      [java]     at
> org.eclipse.persistence.queries.DatabaseQuery.prepareCall(DatabaseQuery.java:1577)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:240)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EJBQueryImpl.buildEJBQLDatabaseQuery(EJBQueryImpl.java:173)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:125)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EJBQueryImpl.<init>(EJBQueryImpl.java:109)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EntityManagerImpl.createQuery(EntityManagerImpl.java:1326)
>      [java]     at
> org.eclipse.persistence.internal.jpa.EntityManagerImpl.createQuery(EntityManagerImpl.java:1348)
>      [java]     at openbook.server.OpenBookService.querySingle(Unknown
> Source)
> 


-----
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