# 7.2.1\. 多對一(many to one) _單向many-to-one關聯_是最常見的單向關聯關系。 ``` <class name="Person"> <id name="id" column="personId"> <generator class="native"/> </id> <many-to-one name="address" column="addressId" not-null="true"/> </class> <class name="Address"> <id name="id" column="addressId"> <generator class="native"/> </id> </class> ``` ``` create table Person ( personId bigint not null primary key, addressId bigint not null ) create table Address ( addressId bigint not null primary key ) ```