javaexceptionsyntaxjpqlejbql

EJB QL Syntax error

In my app, I have the following 2 entities:

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class Commentable implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    protected Long id;
    protected long createdDate;
    ...
}

@Entity
public class Announcement extends Commentable implements Serializable { 

    private int    type;  
    private String title;
    @Column(columnDefinition = "MEDIUMTEXT")
    private String content;
    ...
}

When I try to get some rows from the Announcement table, I keep getting syntax error on the following line: 

Query q = em.createQuery("SELECT A FROM Announcement A JOIN Commentable C ON A.id = C.id WHERE A.type=:type ORDER BY C.createdDate DESC");

This is the stacktrace:

Caused by: Exception [EclipseLink-8023] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.JPQLException
Exception Description: Syntax error parsing the query [SELECT A FROM Announcement A JOIN Commentable C ON A.id = C.id WHERE A.type=:type ORDER BY C.createdDate DESC].
Internal Exception: org.eclipse.persistence.internal.libraries.antlr.runtime.EarlyExitException

I'd be very grateful if you could tell me what I have done wrong here.

Best regards, James Tran

Solution

  • If Announcement extends Commentable, you shouldn't need a join:

    select a from Announcement a where a.type = :type order by a.createdDate desc