7.3. Unidirectional associations with join tables
7.3.1. One-to-many
A unidirectional one-to-many association on a join table is the preferred option. Specifying
unique="true"
, changes the multiplicity from many-to-many to one-to-many.
<class name="Person"> <id name="id" column="personId"> <generator class="native"/> </id> <set name="addresses" table="PersonAddress"> <key column="personId"/> <many-to-many column="addressId" unique="true" class="Address"/> </set> </class> <class name="Address"> <id name="id" column="addressId"> <generator class="native"/> </id> </class>
create table Person ( personId bigint not null primary key ) create table PersonAddress ( personId not null, addressId bigint not null primary key ) create table Address ( addressId bigint not null primary key )