Ummmm.....
You should use <one-to-many> or <many-to-many>
<many-to-one> makes no sense at all.....
jiesheng zhang
<[EMAIL PROTECTED]> To: [EMAIL PROTECTED]
Sent by: cc:
[EMAIL PROTECTED] Subject: [Hibernate] should
<many-to-one> be added to <bag><list>...?
eforge.net
03/02/03 06:11 PM
I have one usage scenario as below:
The classes could be like this.
public class Person {
...
List Addresses; //A list of Address objects.
}
public class Address {
...
List types; //A list of AddressType object
}
public class AddressType {
long typenum;
String typename;
}
The database schema could be like this.
creat table addressType (
typenum varchar(20) primary key,
typename varchar(40) not null
);
/*
* Table models a collection of address type.
*/
create table addressTypes (
collectionID integer,
type integer,
constraint FK_ADDRESSTYPE_TO_STRING foreign key
(type) references addresstype (typenum)
);
create sequence seq_ats;
create table person (
id integer primary key,
...
);
create table address (
personid integer not null,
...
types integer, /* The type references the
collectionID in the AddressTypes above */
constraint FK_ADDRESS_TO_PERSON foreign key
(companyid) references person (id)
);
The mapping file is like this
<hibernate-mapping>
<bag role="addressTypes" table="addressTypes">
<generated-key type="long" column="collectionID">
<generator class="sequence">
<param>seq_ats</param>
</generator>
</generated-key>
<composite-element class="AddressTypeWrapper">
<many-to-one name="type" column="type"
class="AddressType"/>
</composite-element>
<!--
here I use one component class AddressTypeWrapper to
wrap the
AddressType object. The AddressTypeWrapper
has only one property: the
AddressType object. So
here the AddressTypeWrapper is really an
artifact
class required for hibernate mapping only, not from
object model.
What I really wants is that the collection element is
type of AddressType,
not AddressTyepWrapper. The
mapping could be like this: <many-to-one name
="type"
column="type"
class="AddressType"/>---<many-to-one>directly under
<bag>.
However this is not allowed by the DTD since bag does
not have
<many-to-one> element.
Is there any other consideration why
<many-to-one> is
not allowed here? or Can I just modify the DTD and use
the
<many-to-one> directly under <bag>.
On a second though
<many-to-one>/<one-to-one> should
be allowed anywhere <property>/<element>
is allowed.
For <property>/<element>, One column produce an
instance of
primitive type. For
<many-to-one>/<one-to-one> one column (and a table) is
used to produce a user-defined type.
-->
</bag>
<!-- map for AddressType -->
<class name="AddressType" table="AddressType">
<id name="typenum" type="long">
...
</id>
<property name="typename" column="typename"/>
</class>
<!-- map for Person -->
<class name="Person" table="person">
...
<!--person has a list of Address -->
<bag name="addresses table="address">
<key column="personid"/>
<composite-element>
...
<!-- references to the top-level collection -->
<collection name="types" column="types"
role="addressTypes"/>
</composite-element>
</bag>
</class>
</hibernate-mapping>
Thanks
jason
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
-------------------------------------------------------
This SF.NET email is sponsored by:
SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
http://www.vasoftware.com
_______________________________________________
hibernate-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/hibernate-devel
**********************************************************************
Any personal or sensitive information contained in this email and
attachments must be handled in accordance with the Victorian Information
Privacy Act 2000, the Health Records Act 2001 or the Privacy Act 1988
(Commonwealth), as applicable.
This email, including all attachments, is confidential. If you are not the
intended recipient, you must not disclose, distribute, copy or use the
information contained in this email or attachments. Any confidentiality or
privilege is not waived or lost because this email has been sent to you in
error. If you have received it in error, please let us know by reply
email, delete it from your system and destroy any copies.
**********************************************************************
-------------------------------------------------------
This SF.NET email is sponsored by:
SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
http://www.vasoftware.com
_______________________________________________
hibernate-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/hibernate-devel
