Problems mapping a manytoone legacy association (Thanks ;-))

ciberado · **Joined:** Thu May 26, 2005 7:25 am **Posts:** 13

Hibernate version: 3

Mapping documents: Annotations

Hi! I have what I think is a quite common situation and I'm just not able to find the appropriate mapping for it. It's a legacy (read, unnormalized) manytoone relationship between two tables that represents a single entity. This is a simplification of the situation:

Code:

CREATE TABLE cities
  (id varchar(8) primary key, 
   name varchar(32), region char(4))

example: BAR87432, "Barcelona", "CAT"

Code:

CREATE TABLE territories
  (regionCode varchar(12) primary key, region char(4))

example: CATA12345678, CAT

Code:

class City {

   String id;               <-- city
   String name;          <-- city
   String regionCode;  <-- territory

}

As you can see, the join is performed over an unique but non-primary-key field (region) and the only property I want to set is the regionCode string value.

Secondary tables doesn't work and I'm just not able to map a ManyToOne because the target property is a String.

Any help would be very appreciated :-)

jv

waswani · **Posted:** Mon Mar 17, 2008 1:36 pm

You can make us of the folowing mapping in the City class mapping provided you change the

String regionCode; --------------to--------------- Territory regionCode;

String class needs to be replaced by Territory class.

<many-to-one name="regionCode" column="regionID" element-ref="region" />

In the above mapping, element-ref will ask the hibernate framework not to use primary key of Territory class instead use what I have given i.e. region.

ciberado · **Joined:** Thu May 26, 2005 7:25 am **Posts:** 13

Thanks a lot waswani :-) But in fact we don't have a Territory entity and we would prefer not to create it: we only need the regionCode as a string... it's would require a long explanation but in this project it just doesn't have enough semantic weight to originate a full Entity.

So we would love to have a simple String attribute. Would it be possible?

Anyway, thanks again.