Composite-id and generator

Arnaud · **Posted:** Wed Dec 17, 2003 6:56 am

Hi all,

Consider a table with a Pk composed by a id and a language code:

Code:

create table A
....
constraint PK primary key (A_ID, A_LANG_CODE)

a sequence gives the value of A_ID.

How do i map the id ? A composite-id id is ok:

Code:

<composite-id>
<key-property name="announceId" column="A_ID" type="long" length="22"/>
<key-property name="announceLangCode" column="A_LANG_CODE" type="string" length="2"/>
</composite-id>

but how can i generate A_ID whith a sequence ? (<generator class> is not working with composite-id)

Thanks in advance.

gavin · **Posted:** Wed Dec 17, 2003 7:07 am

Think about it: A_ID is already unique, since it is assigned from the sequence. So including A_LANG_CODE in the PK is redundant.

right?

Arnaud · **Posted:** Wed Dec 17, 2003 8:13 am

gavin wrote:

Think about it: A_ID is already unique, since it is assigned from the sequence. So including A_LANG_CODE in the PK is redundant.

right?

it's not right conceptually. I explain: the same "entity" is recorded in database in various languages. So the A_ID is the same with different A_LANG_CODE. Example:
"1", "fr"
"1", "en"
"1", "de"
"2", "fr"
"2", "de"
...etc

gavin · **Posted:** Wed Dec 17, 2003 8:29 am

Ahah! So actually it makes no sense to handle this with a <generator> tag ;)

The application needs to assign the sequence value. So just do it.

Arnaud · **Posted:** Wed Dec 17, 2003 1:34 pm

Ok u convince me !

So before saving an object i retrieve the value of the sequence:

Quote:

Statement statement = session.connection().createStatement();
ResultSet resultSet = statement.executeQuery("select S_AIS.NEXTVAL from dual");

I'am not sure that's a good solution. So if u have a better one...

emmanuel · **Posted:** Wed Dec 17, 2003 2:29 pm

Having A object and a map having language key and containing components containing properties specific to each language.
Not sure I'm clear, but the idea is to separate the A notion from the language notion