Occasionally duplicated entries on using ManyToMany

michael.kohlhuber · **Joined:** Wed Jan 16, 2008 8:16 am **Posts:** 23

Duplicated entries on using ManyToMany

Hi,

I'm working with a legacy database, that's why the database schema isn't that
fine. I'm using following classes:

Code:

@Entity
@Table(name = "TS_STATI")
class Status {

    @Id
    @Column(name = "STATUS_ID")
    private Long id;

    @ManyToMany
    @JoinTable(name = "TEXT2STATI2NAME", 
            joinColumns = { 
                @JoinColumn(name = "MAP_ID") 
                },
            inverseJoinColumns = { 
                @JoinColumn(name = "TEXT_ID", referencedColumnName = "TEXT_ID") 
                })
    private List<TextResource> nameLocalized;

}

@Entity
@Table(name = "TEXT_RESSOURCE")
class TextResource {

    @Id
    @Column(name = "ROWID")
    private String id;

    @Column(name = "TEXT_ID")
    private Long textId;

    @Column(name = "SPRACHE")
    @Type(type = "LocaleType")
    private Locale locale;
    
    @Column(name = "TEXT")
    private String text;

}

As can imagine, the TextResource contains translations.

When i quering

Code:

from Status

the status object - in one of ten cases -
the TextResource list contains duplicate entries (e.g. three times the french
translation) and not one for each language.

The generated sql works fine.

Code:

SELECT namelocali0_.map_id AS map1_1_, namelocali0_.text_id AS text2_1_,
       textresour1_.ROWID AS rowid1_132_0_,
       textresour1_.sprache AS sprache132_0_, textresour1_.text AS text132_0_,
       textresour1_.text_id AS text4_132_0_
  FROM text2stati2name namelocali0_, text_ressource textresour1_
 WHERE namelocali0_.text_id = textresour1_.text_id(+)
       AND namelocali0_.map_id = ?

Is it a hibernate bug or did I configure it in a wrong way. Maybe it has to
do with the ROWID or... Of course it is also not a pure m:n relation. It is
something like 1:1:n.

Hibernate Version: 3.2.6ga, Database Oracle: 9.

I hope you can help me.

Thank you in advance.

Best regards, Michi

Cameron McKenzie · **Posted:** Thu Jun 26, 2008 9:29 am

You could use a Set instead of a List, which would eliminate duplicate entries?

michael.kohlhuber · **Joined:** Wed Jan 16, 2008 8:16 am **Posts:** 23

thank you for you quick replay. that would be ok for me, but the real problem is, that one of the list get duplicated and the rest got lost.

one example:
StatusA has following translations: DE:Status and EN:State. When loading it with hibernate the list contains EN:State twice and DE:Status get lost.

So, the list doesnt help me a lot.

Best regards, Michi