I am trying to write the mappings for a one to one relationship. The problem is I have two tables, both have an "estimate_number" field which is the primary key. How would you map the one to one relationship?

Thanks,
Jeff.

See Online manual for further details:

There are two varieties of one-to-one association:
* primary key associations
* unique foreign key associations

Primary key associations don't need an extra table column; if two rows are related by the association then the two table rows share the same primary key value. So if you want two objects to be related by a primary key association, you must make sure that they are assigned the same identifier value!

For a primary key association, add the following mappings to Employee and Person, respectively.

<one-to-one name="person" class="Person"/>

<one-to-one name="employee" class="Employee" constrained="true"/>

Alternatively, a foreign key with a unique constraint, from Employee to Person, may be expressed as:

<many-to-one name="person" class="Person" column="PERSON_ID" unique="true"/>

And this association may be made bidirectional by adding the following to the Person mapping:

<one-to-one name"employee" class="Employee" property-ref="person"/>