在hibernate中关于外键一对一的问题，如何设置呀，我看了半天的书，都不明白，请高手帮忙

Question

user表：
+-----------+------------+-------+------------+--------+
|Field Name | Field Type | size  |  Comment   |  index |
+-----------+------------+-------+------------+--------+
|    id     |   INTEGER  |  11   |  自动编号  |  主键  |
+-----------+------------+-------+------------+--------+
|    bh     |   VARCHAR  |  30   |  用户编号  |  外键  |
+-----------+------------+-------+------------+--------+
|   name    |   VARCHAR  |  20   |  用户姓名  |        |
+-----------+------------+-------+------------+--------+
user_detail表：
+-----------+------------+-------+------------+--------+
|Field Name | Field Type | size  |  Comment   |  index |
+-----------+------------+-------+------------+--------+
|    id     |   INTEGER  |  11   |  自动编号  |  主键  |
+-----------+------------+-------+------------+--------+
|    bh     |   VARCHAR  |  30   |  用户编号  |  外键  |
+-----------+------------+-------+------------+--------+
|  content  |   VARCHAR  |  200  |  备注信息  |        |
+-----------+------------+-------+------------+--------+
我想是这两张表实现外键user.bh = user_detail.bh的一对一关联，如何写hbm.xml和构造函数呢？我看了半天的书，都不明白，请高手帮忙

Answer 1

public class User implements Serializable {

    private Integer id;    private UserDetail bh;    private String name; /**
 * @hibernate.id
 * column="id"
 * unsaved-value="null"
 * generator-class="sequence"
 * @hibernate.generator-param
 * name="sequence"
 * value="user_seq"
 */
public Integer getId() {
return id;
} public void setId(Integer id) {
this.id = id;
} /**
 * @hibernate.many-to-one
 * column="UserDetail_id"
 * cascade="save-update"
 * inverse="true"
 * class="XXXX.XXXXX.UserDetail"
 */
public UserDetail getBh() {
return bh;
} public void setBh(UserDetail bh) {
this.bh = bh;
} /**
 * @hibernate.property
 * column="name"
 */
public String getName() {
return name;
} public void setName(String name) {
this.name = name;
}
}<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class
        name="xxxx.xxxx.User"
        table="User">
         <id name="id"
            column="id"
            type="int"
            unsaved-value="null" >
            <generator class="sequence">
                <param name="sequence">car_seq</param>
            </generator>
        </id>
        <many-to-one
            name="bh"
            class="xxxx.xxxx.UserDetail"
            cascade="save-update"
            outer-join="auto"
            column="UserDetail_id"
        />
        <property
            name="name "
            type="java.lang.String"
            column="name"
        />User_Detail我就不写了。按照上面写，上面实现的是1对1单向关联，通过User可以User.bh拿到UserDetail.如果要做双向，在User_Detail也添加<many-to-one> 因为<many-to-one>可以表术单向MANY-TO-ONE，ONE一端和ONE-TO-ONE，2端的关系。

Answer 2

两个vo类代码：package OneToOne;public class Person {
private Integer id ;
private String name ;
private Integer age ;

private IDCard idCard ;
/**
         getter和setter方法省略
        */
}package OneToOne;public class IDCard {
private Integer id ;

private String serial; private Integer expiry; private Person person;        /**
         getter和setter方法省略
        */  
}Idcard.hbm.xml文件：
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="OneToOne.IDCard" table="idcard">
<id name="id" column="id" type="java.lang.Integer">
<generator class="foreign">
<param name="property">person</param>
</generator>
</id> <one-to-one name="person"
class="OneToOne.Person" constrained="true">
</one-to-one> <property name="serial" type="java.lang.String">
<column name="serial" length="18" not-null="true" />
</property>
<property name="expiry" type="java.lang.Integer">
<column name="expiry" not-null="true" />
</property>
</class>
</hibernate-mapping>Person.hbm.xml文件：
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping>
<class name="OneToOne.Person" table="person">
<id name="id" type="java.lang.Integer">
<column name="id"  />
<generator class="native"></generator>
</id>
<property name="name" type="java.lang.String">
<column name="name" length="20" not-null="true" />
</property>
<property name="age" type="java.lang.Integer">
<column name="age" />
</property>
<one-to-one name="idCard"
class="OneToOne.IDCard" cascade="all"
outer-join="true">
</one-to-one>
</class>
</hibernate-mapping>