Hi guys,

I'm new to hibernate, so I need some advice to decide if I can
implement it for my system.
I have a huge database, containing lots of articles in different
tables. All the table structures are the same, except the table names,
because each table belongs to a different magazine. I know many would
say that it is better to keep one article table with a distinguishing
column for a magazine, but now every table may contain thousands of
records, and it was done for performance reasons.
So, the tables are named `1`, `2`, `3`, `4`, etc, and has columns like
article_id, title, lead, body, etc.

Now the question is, I was wondering if I would be able to map those
tables in Java using hibernate, say, having an entity called
Article.java, but somehow dynamically map it to a necessary table in
the database during the run. And moreover, what would happen if I
needed two articles from two different tables, say
magazines.`1`.article_id=23 and magazines.`323`.article_id=12
Is it even feasible?

I have implemented it all manually now, using jdbc and simple sql
select statements, and in my selects I just supply the table names on
the run.
But as far as I know, Hibernate uses a hibernate-mapping file, where
the table names are hardcoded.

Highly appreciate any advice!
Thanks a lot in advance

/progre55

Thousands of records should not be any problem for any decent database to handle. Not even millions if properly indexed should be any problem. I suggest you use one table only and add a magazine_id column to it.

also clever databases can split such a tables by DB configuration, like you can set a rule "split on magazine_id" to have physically separated tables/stores/disks/... and you can still query them all as one in the rare occasions you would like to, or it will be clever in handling a "where magazine_id"..

If this is really huge and your database doesn't support this clever options (don't remember the list now) you might have a look into Hibernate Shards which provides a similar solution at a higher level. Never a good idea to have to deal with these details in your code :)

so, if I'm not changing the database structure, are you saying it is not possible to implement hibernate? having the current database structure..

It is possible to use Hibernate, but it may not be as smooth as if you only had one table. It is possible to map a single class to multiple tables using the entity-name attribute as described by http://docs.jboss.org/hibernate/stable/ ... entityname. As far as I know you are limited to use XML mappings files, but you'll need one mapping file for each table with articles. You can probably write some kind of script to automatically generate those. It should even be possible to generate the proper XML when your application starts and then register with Configuration.addDocument().

When you are handling Article objects, you'll also need to keep track of which entity-name they belong to. I don't think Hibernate does this since you need to use the two-argument methods like Session.get(entityName, id), Session.save(entityName, object), etc. You may want to have a look at the org.hibernate.Interceptor interface. There are some entity-name-related methods that may be useful. Note that I don't have much experience with this so I am not really aware of what may pop up or any smart solutions.