Hi,

How can I map between two tables having the composite primary keys on both the table. The reference key as well is a combination of two columns.

Scenario:

I created the following tables using Oracle 10g

create table POINT (
ID INTEGER not null,
CD INTEGER not null,
TYPE INTEGER,
NAME VARCHAR2(256)
)

alter table POINT
add constraint "PointPK" primary key (ID, CD)

create table POINTTYPE (
ID INTEGER not null,
TYPE INTEGER not null,
DESCR VARCHAR2(256)
)

alter table POINTTYPE
add constraint POINTTYPEPK primary key (ID, TYPE)

alter table POINT
add constraint POINTFK01 foreign key (ID, TYPE)
references POINTTYPE (ID, TYPE)

I have set up the following in the hbm file for PointType

<class name="PointType,PointType" table="POINTTYPE">
<composite-id name="PointTypeMultiPKey" class="PointTypeMultiPKey,PointType">
<key-property name="Id" column="ID" type="integer" />
<key-property name="Type" column="TYPE" type="integer" />
</composite-id>
<property name="Descr" column="DESCR" type="string" />
</class>


I give the following in hbm for Point
<class name="Point,PointType" table="POINT">
<composite-id name="PointMultiPKey" class="PointMultiPKey,PointType" >
<key-property name="Id" column="ID" type="integer" />
<key-property name="Cd" column="CD" type="integer" />
</composite-id>
<many-to-one name="PointType" unique="true" class="PointType,PointType" column="TYPE"/>
<property name="PointName" column="NAME" type="string" />
</class>

NHibernate gives error for '<many-to-one name="PointType"'

ERROR - NHibernate.MappingException: Foreign key in table POINT must have same number of columns as referenced primary key in table POINTTYPE
at NHibernate.Mapping.ForeignKey.set_ReferencedTable(Table value)
at NHibernate.Cfg.Configuration.SecondPassCompileForeignKeys(Table table, ISet done)

However, Oracle DDL scripts are creating these table without giving any error.
How can I get this working thru NHibernate?



Thanks,
Suman Sajjana

Hi,

I have more or less the same problem.

Did you manage to solve your problem?

As far as I'm concerned, I'd like to map those 2 tables:

continent (id_continent, id_language_data, continent)
country(id_country, id_language_data, id_continent, country)

The problem is that id_language_data is both part of the composite primary key and the composite foreign key



I think it could involve problems in updating data.
What do you think?


Thanks
Guillaume

I saw an example in the documentation once and according to it your mapping would need to be written as:



Try this to see if it works