I have this too tables:

CREATE TABLE PersonalData(
ID_PersonalData VARCHAR2(20) NOT NULL,
ID_Person VARCHAR2(20) NOT NULL,
other VARCHAR2(20)
CONSTRAINT PK46 PRIMARY KEY (ID_PersonalData,ID_Person)
);

CREATE TABLE Person
ID_Person VARCHAR2(20) NOT NULL,
otherfield VARCHAR2(20)
CONSTRAINT PK31 PRIMARY KEY (ID_Person)
);
And i need ID_PersonaData like a generated identifier ..
How can i do that ? ..
I never map two ids in the same table without composite-id, and in this case is not posible ... !!
Please help ..

Well, maybe you could precise your needs.

It's not possible to map a table that has more than one primary key without using composite id. But there are two ways for doing this: using a special composite class to store the ids (recommended method), or directly storing the props without any new class.

You have got two posible solutions:

1.- Use a surrogate keys in yor PersonalData table. Composite keys make more difficult the maintenance. Then. you can creata an unique constraint in your database with ID_PersonalData and ID_Person columns (this combination of columns are a candidate key).


2.- I suppose than the column ID_Person of your PersonalData table is a foreign key from Person Table. If one instance of PersonalData hasn't got its own lifecycle, you can understaand the class PersonalData how a type value from Person class. You must mapped the class Person how:

ok .. but i need that id_PersonData by generated .. how can i do that ?
Thanks for your replies ..

This two tables can not be change, the model is already deployed and the person_id is a foreign key of the table PersonalData but also a key so .. I need to generate the ID_PersonalData .. and the idea of a UserType Composite-Id that use a generator to do that make sense ..
dont you think ??
What others option do i have ??

If you need that ID_Personal_data would be a generated identifier, then, the primary key of your PersonalData table must be an unique column, ID_PersonalData. Think in it. This column will be unique and not-null, you can use it how primary key.

Then, you can make an unique constraint in your database with the columns ID_PersonalData and ID_Person. (This constarints it hasn't got munh sense, because one column is unique yet).

Yes .. but what about the composite-id .. how i make it to one of the Keys been generated .. in this case PersonalData Id .. ??
I was reading in the night, and seems like i have to implement a CompositeUserType and IdentifierGenerator for that .. ?
is that true ??
There no something already for this http://hibernate.bluemars.net/117.html?cmd=prntdoc

If you need than one key (ID_Personaldata) would be generated, you don't need a composite key, because ID_Personaldata is yet a primary key (is unique and is not-null).

Which is the reason by you have a composite-id?

Imo, if your tables really cannot change: you have only one solution. Map the columns as a composite-id as it has to (since it is a composite primary key) and manage the sequence by yourself to set one of those columns.

Write some wrapping code that will retrieve the next sequence number you need, then just set it manually.

I'm not sure there's another way for you at the moment.

i´m in that situation .. i can´t change the design of the dataBase .. so .. i hear that you can do that with COmpositeUserType and identifierGenerators .. but. there is no example or other reading that help to implement that . !!