hibernate mapping issue

[jay desi]

all,

I am a hibernate newbie.

I work with an older mysql database. This schema does not have foreign-key constraints between various
tables syntactically. Although, conceptually speaking, there are many foreign-key relationships between these tables.

Eg:- This is a sample table :-

 


create table Item(   
item_id bigint(20) NOT NULL default '0',   
item_name varchar(80) default NULL,   
PRIMARY KEY  (`item_id`)   
)ENGINE=MyISAM DEFAULT CHARSET=latin1   
  
create table Item_Details(   
item_detail_id bigint(20) NOT NULL default '0',   
item_id bigint(20) NOT NULL default '0',   
item_detail_date datetime NOT NULL default '0000-00-00 00:00:00',   
PRIMARY KEY  (`item_detail_id`),   
KEY `II` (`item_id`)   
)ENGINE=MyISAM DEFAULT CHARSET=latin1 

The second table ideally should have been:-

  

create table Item_Details(
item_detail_id bigint(20) NOT NULL default '0',
item_id bigint(20) NOT NULL default '0' [u]references Item(item_id),[/u]
item_detail_date datetime NOT NULL default '0000-00-00 00:00:00',
PRIMARY KEY  (`item_detail_id`),
KEY `II` (`item_id`)
)ENGINE=MyISAM DEFAULT CHARSET=latin1

However, I cannot modify schema now.My question is that Can I still use Hibernate annotations here.
Can I still use @OneToMany if there are no foreign key constraints on database tables?

[David Newton]

What happened when you tried it, and wouldn't that have been quicker?

I'm not aware that Hibernate checks itself against DB metadata--all it cares about is what you tell it.

[jay desi]

david...thanks for a quick reply..
I cannot modify schema because I am not allowed to do so...its a very old db schema..

[Cameron Wallace McKenzie]

Well, you've got the foreign key, you just don't have the constraint, right? I think this will be okay.

-Cameron McKenzie

[jay desi]

thanks cameron...Oh and going through some tutorials mentioned in your signature..They seem to be very good.

[jay desi]

I tried to create an entity class from database in netbeans using hibernate. However, one of the db table
does not have a primary key, but an index. And it didnt allow me to create an entity class frm that table.
So, I guess we cannot use hibernate to map table to object if we dont have any primary key. Am
I correct?

[David Newton]

If you're trying to create it *automatically* then no--there's no way for the conversion process to read your database's mind.

Do it manually.