Question

Maybe I’m not seeing it, but what’s wrong with specifying the group?

Difficulty querying the database (currently empty):

public void persist(Msg message) {
    LOG.info("\t" + message);
    LOG.info("isOpen?" + em.isOpen());
    em.getTransaction().begin();
    int id = message.getId();
    TypedQuery<Notes> q = em.createQuery("SELECT  n "
            + "FROM Notes n WHERE n.messageId = :messageId "
            + "AND n.group = :group", Notes.class);
    q.setParameter("messageId", message.getId()).setParameter("group", message.getGroup());
    List<Notes> results = q.getResultList();
    em.getTransaction().commit();
    for (Notes o : results) {
        LOG.info("object is \n\n" + o);
    }
}

stack trace:

run:
May 10, 2012 7:17:17 AM net.bounceme.dur.usenet.controller.PropertiesReader getProps
INFO: NNTP.loadMessages...
[EL Info]: 2012-05-10 07:17:27.343--ServerSession(29959998)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Severe]: 2012-05-10 07:17:29.315--ServerSession(29959998)--Local Exception Stack: 
Exception [EclipseLink-8025] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.JPQLException
Exception in thread "AWT-EventQueue-0" java.lang.ExceptionInInitializerError
Exception Description: Syntax error parsing the query [Notes.getByIdAndGroup: SELECT DISTINCT n FROM Notes n WHERE n.messageId = :messageId AND n.group=group], line 1, column 74: unexpected token [group].
Internal Exception: NoViableAltException(34@[792:1: comparisonExpressionRightOperand returns [Object node] : (n= arithmeticExpression | n= nonArithmeticScalarExpression | n= anyOrAllExpression );])
    at net.bounceme.dur.usenet.swing.Frame.panelWithTable1PropertyChange(Frame.java:121)
    at net.bounceme.dur.usenet.swing.Frame.access$100(Frame.java:12)
    at net.bounceme.dur.usenet.swing.Frame$2.propertyChange(Frame.java:51)

database:

thufir@dur:~$ 
thufir@dur:~$ mysql -u java -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 141
Server version: 5.1.58-1ubuntu1 (Ubuntu)

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 
mysql> describe nntp.notes;
+------------+------------+------+-----+---------+-------+
| Field      | Type       | Null | Key | Default | Extra |
+------------+------------+------+-----+---------+-------+
| ID         | bigint(20) | NO   | PRI | NULL    |       |
| GROUP_ID   | int(11)    | NO   |     | NULL    |       |
| STAMP      | date       | NO   |     | NULL    |       |
| NOTE       | text       | YES  |     | NULL    |       |
| MESSAGE_ID | int(11)    | NO   |     | NULL    |       |
| GROUP      | text       | NO   |     | NULL    |       |
+------------+------------+------+-----+---------+-------+
6 rows in set (0.03 sec)

mysql> quit;
Bye
thufir@dur:~$ 

Should this class be Note or Notes? Similarly should the table be Note or Notes? Maybe it doesn’t matter.

Entity:

package net.bounceme.dur.usenet.controller;

import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
import javax.xml.bind.annotation.XmlRootElement;

@Entity
@Table(name = "notes", catalog = "nntp", schema = "")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Notes.findAll", query = "SELECT n FROM Notes n"),
    @NamedQuery(name = "Notes.findById", query = "SELECT n FROM Notes n WHERE n.id = :id"),
    @NamedQuery(name = "Notes.findByGroupId", query = "SELECT n FROM Notes n WHERE n.groupId = :groupId"),
    @NamedQuery(name = "Notes.findByStamp", query = "SELECT n FROM Notes n WHERE n.stamp = :stamp"),
    @NamedQuery(name = "Notes.findByMessageId", query = "SELECT n FROM Notes n WHERE n.messageId = :messageId"),
    @NamedQuery(name = "Notes.getByIdAndGroup", query = "SELECT DISTINCT n FROM Notes n WHERE n.messageId = :messageId AND n.group=group"),
})
public class Notes implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @Basic(optional = false)
    @Column(name = "ID", nullable = false)
    private Long id;
    @Basic(optional = false)
    @Column(name = "GROUP_ID", nullable = false)
    private int groupId;
    @Basic(optional = false)
    @Column(name = "STAMP", nullable = false)
    @Temporal(TemporalType.DATE)
    private Date stamp;
    @Lob
    @Column(name = "NOTE", length = 65535)
    private String note;
    @Basic(optional = false)
    @Column(name = "MESSAGE_ID", nullable = false)
    private int messageId;
    @Basic(optional = false)
    @Lob
    @Column(name = "GROUP", nullable = false, length = 65535)
    private String group;

    public Notes() {
    }

    public Notes(Long id) {
        this.id = id;
    }

    public Notes(Long id, int groupId, Date stamp, int messageId, String group) {
        this.id = id;
        this.groupId = groupId;
        this.stamp = stamp;
        this.messageId = messageId;
        this.group = group;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public int getGroupId() {
        return groupId;
    }

    public void setGroupId(int groupId) {
        this.groupId = groupId;
    }

    public Date getStamp() {
        return stamp;
    }

    public void setStamp(Date stamp) {
        this.stamp = stamp;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }

    public int getMessageId() {
        return messageId;
    }

    public void setMessageId(int messageId) {
        this.messageId = messageId;
    }

    public String getGroup() {
        return group;
    }

    public void setGroup(String group) {
        this.group = group;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Notes)) {
            return false;
        }
        Notes other = (Notes) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "net.bounceme.dur.usenet.controller.Notes[ id=" + id + " ]";
    }

}

Right now I’m just using the one table, but can’t seem to get a working query.

Answer 1

Syntax error parsing the query [Notes.getByIdAndGroup: SELECT DISTINCT n FROM Notes n WHERE n.messageId = :messageId AND n.group=group], line 1, column 74: unexpected token [group].

In SQL, GROUP is a reserved word, which is probably the reason for this error message. In JPA2 it should be possible to quote the column name in the query by changing the annotation to

@Column(name="\"GROUP\"")

If that does not work in your case, your best bet would be to change the database column and annotation to something like GROUP_NAME.