Hi all. I have a newbie question about a mapping. I have two tables. One, the primary table, is called Building, while the second one is used to stored Building addresses (called Address). There is an one-to-one mapping between these two tables, which are related through an id property, called bid. This is primary key for the Building table and foreign key for the table Address.

According to the current policy a building usually has an address but may not have one sometimes (if its a new entry). How could I write the above mapping in my hbm files? Thanks in advance

anyone?

I think it's a simple situation due to what you described. It's an one-to-one non-bidirectional relation and Building doesn't need to know about Address , so if one is newly built and hasn't got an address, leave it that way. Once you have address for it, create new Address object with primary key is the bid.

could you show me an example of how I could write this? My current one-to-one mapping does not work :(

The mapping file should look like this:




Notice that generator of Address is "assigned", indicate that Address must have the same identifier as Building.

Hey,

I just tried this. But the data I get are nulls. Here is my mappings

<hibernate-mapping>
<class name="org.app.foundation.beans.Gipeda" table="buildings" catalog="buildings_gr">
<id name="gid" type="string">
<column name="id" length="35" />
<generator class="assigned" />
</id>
.............................................
<one-to-one name="map" class="org.app.foundation.beans.GeoMap" constrained="true"/>
</class>
</hibernate-mapping>


and

<hibernate-mapping>
<class name="org.app.foundation.beans.GeoMap" table="maps" catalog="buildings_gr">
<id name="gid" column="gid">
<generator class="native"/>
</id>
<property name="latitude" type="string" not-null="true" />
<property name="longitude" type="string" not-null="true" />
</class>
</hibernate-mapping>

But what I get is null data. Actually a building may not have a geomap (or can have at most one). But i would expect at least the gid of the geomap object to be populated. But I dont get data even for the entries that do have a map associated. Thanks for the help