映射一对一关联

1.外键映射

public Class Mobile{

  private String sn;

  private String model;

  private String brand;

  private SimCard simCard;

}

public Class SimCard{

  private String sn;

  private String isp;

  private Mobile mobile;

}

<one-to-one name="simCard" class="*.SimCard" property-ref="mobile" />

<many-to-one name="mobile" class="*.Mobile" column="mobile_sn" unique="true"/>