@Index not working?

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Hello,

I'm rather new to Hibernate so I guess I'm just doing something stupid, so any help greatly appreciated...
I'm using JBoss 4.0.5 with EJB3 profile. I'm trying to create database indexes using Hibernate @Index annotation, so I have an Entity like:

Code:

@Entity
@Table(name="keyword")
@org.hibernate.annotations.Table(appliesTo="keyword", indexes={
      @Index(name="keywordIndex", columnNames={ "keyword" })
})
public class Keyword implements Serializable
{
  // ...

    @Column(name="keyword")
    public String getKeyword()
    {
       return keyword;
    }
}

... but no indexes are being created. What am I doing wrong?
Thanks!
Adam

emmanuel · **Posted:** Wed Jul 25, 2007 3:06 pm

and hibernate.hbm2ddl.auto is set to create?
Which version of HAnnotation are you using (you can see that in the log file)? can you try with the latest version

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Thanks a lot! Indeed I had hibernate.hbm2ddl.auto=update; setting it to create did the trick. But as a side effect it seems that now with every start of the server the database schema is re-created and I lost all the data. Is it possible to avoid that?

emmanuel · **Posted:** Thu Jul 26, 2007 1:36 pm

if you want to be able to update the schema each time you deploy wo losing data, no.
But update should not be done in production.
People usually use the schemaexport ant task to generate a DDL file that they apply manually in prod.
In dev mode data usually is create with unit tests each time

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Well, the problem is that the data for my application (for development mode) is rather vast so I don't want to recreate it too often. But now every time I change the DB schema I deploy with hibernate.hbm2ddl.auto=create and re-create the data and otherwise just deploy with hibernate.hbm2ddl.auto=update and it works just fine for me. So thanks a lot for your help.

One more question if I may: is it possible to create indexes for join tables? (for instance coming with M-N relations). I did not manage to do that... any hints?

Cheers,
Adam

emmanuel · **Posted:** Thu Aug 02, 2007 3:04 pm

not today, but I never understood the need provided that the PK are expressed already

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Right you are. The problem is I don't know how to specify the primary key for a join table via EJB3 annotations. Do you happen to know how to do that?

emmanuel · **Posted:** Fri Aug 03, 2007 2:39 pm

you don't need to, Hibernate knows which columns are part of the PK if a PK makes sense.

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

I'm not sure if I understand what do you mean. I happen to have a many-to-many relationship and I end up with having a join table with no primary key (I'm using postgresql). How can I enforce that the PK is specified?

emmanuel · **Posted:** Tue Aug 07, 2007 1:57 pm

Maybe you're using a bag where pk are undefined.

andydale · **Posted:** Tue Aug 07, 2007 2:01 pm

Hi,

I also use PostgreSQL, and a @ManyToMany creates a join table with 2 foreign keys (as expected), and also a composite primary key on both of the fk's.

Cheers,

Andy

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Hmm... My field looks as follows:

Code:

@ManyToMany(cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
@JoinTable(name="task_catPositionsClosure")
public Collection<CatalogueEntry> getCatPositionsClosure()

and as a result I obtain a postgresql table with two foreign keys but with no primary key. Any ideas what am I doing wrong?
Thanks in advance!
Adam

andydale · **Posted:** Tue Aug 07, 2007 2:14 pm

how is the other side of the relationship defined ?

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Ahh, sorry, here it goes:

Code:

@ManyToMany(mappedBy="catPositionsClosure")
public Set<Task> getCatEntryTasks()
{
return catEntryTasks;
}

At first I thought that indeed this is due to the use of Set but I changed it to Collection and still no primary key is being created...
Adam

koper · **Joined:** Tue Jul 24, 2007 9:14 am **Posts:** 8

Dear Andy,

Quote:

I also use PostgreSQL, and a @ManyToMany creates a join table with 2 foreign keys (as expected), and also a composite primary key on both of the fk's.

Can you show me how do you define relations so that you get a composite primary key?
Thank a lot,
Adam