hibernate 关联关系映射

映射关系：

Many-to-one单向

Person – department

Person:

publicclassPerson
implements Serializable{
    private Stringpno;
    private Stringname;
    private Stringaddress;
    private DepartmentEntitydept;
    privateintage;

}

Person.hbm.xml ：
<classname="com.etc.entity.doubleface.Person"table="t_mtoo3_person">
       <idname="pno"><generatorclass="uuid"/></id>
       <propertyname="name"/>
       <propertyname="address"/>
       <propertyname="age"/>
       <many-to-onename="dept"column="deptid"></many-to-one>
    </class>

 

DepartmentEntity:

publicclass DepartmentEntityimplements Serializable{
    privatestaticfinallongserialVersionUID
= 1L;
    private Stringdeptno;
    private Stringdeptname;
    private Stringdeptaddress;

}

DepartmentEntity.hbm.xml：

<classname="com.etc.entity.doubleface.DepartmentEntity"table="t_mtoo3_dept">
       <idname="deptno"><generatorclass="uuid"/></id>
       <propertyname="deptname"/>
       <propertyname="deptaddress"/>
    </class>

 

Many-to-one双向 One-to-many：（去掉任意一边关系配置就成单向）

多个Person对一个 department 

一个department对多个Person：

Person:

publicclassPerson
implements Serializable{
    private Stringpno;
    private Stringname;
    private Stringaddress;
    private DepartmentEntitydept;
    privateintage;

}

Person.hbm.xml:

<classname="com.etc.entity.doubleface.Person"table="t_mtoo3_person">
       <idname="pno"><generatorclass="uuid"/></id>
       <propertyname="name"/>
       <propertyname="address"/>
       <propertyname="age"/>
       <many-to-onename="dept"column="deptid"></many-to-one>
    </class>

DepartmentEntity:

publicclass DepartmentEntityimplements Serializable{
    privatestaticfinallongserialVersionUID
= 1L;
    private Stringdeptno;
    private Stringdeptname;
    private Stringdeptaddress;
    privateSet
persons;

}

DepartmentEntity.hbm.xml:

    <classname="com.etc.entity.doubleface.DepartmentEntity"table="t_mtoo3_dept">
       <idname="deptno"><generatorclass="uuid"/></id>
       <propertyname="deptname"/>
       <propertyname="deptaddress"/>
       <setname="persons">
           <keycolumn="deptid"></key>
           <one-to-manyclass="com.etc.entity.doubleface.Person"/>
       </set>
    </class>

One-to-one

一个学生对应一个学号（主键双向关联）

Student- StudentNo

Student：

publicclass Student {
    private Stringid;
    private StudentNostuno;
    private Stringname;
    privateintage;

}

Student.hbm.xml：

<classname="com.etc.entity.onetoone.Student"table="t_otoo_student">
        <idname="id">
           
<generator
class="foreign">
             
<param name="property">stuno</param>
        </generator>
       
</id>
       <propertyname="name"/>
       <propertyname="age"/>
       <one-to-onename="stuno"constrained="true"></one-to-one>
    </class>

 

StudentNo：

publicclass StudentNo {
    private Stringsno;
    private Stringmem;
    private Studentstu;

}

StudentNo.hbm.xml：

<classname="com.etc.entity.onetoone.StudentNo"table="t_otoo_stuno">
       <idname="sno"><generatorclass="uuid"/></id>
       <propertyname="mem"/>
       
<one-to-one
name="stu"/>
</class>

One-to-one

一个学生对应一个学号（外键双向关联）

Student- StudentNo

Student：

publicclass Student {
    private Stringid;
    private StudentNostuno;
    private Stringname;
    privateintage;

}

 Student.hbm.xml:

<classname="com.etc.entity.onetoonefk.Student"table="t_otoofk_student">
        <idname="id">
           
<generator
class="uuid">
        </generator>
       
</id>
       <propertyname="name"/>
       <propertyname="age"/>
       <many-to-onename="stuno"
            column="stunoid"
        unique="true"
        not-null="true"cascade="save-update"/>
    </class>

 

StudentNo:

publicclassStudentNo{
    private Stringsno;
    private Stringmem;
    private Studentstu;

}

StudentNo.hbm.xml:

<classname="com.etc.entity.onetoonefk.StudentNo"table="t_otoofk_stuno">
       <idname="sno">
           <generatorclass="uuid"/>
       </id>
       <propertyname="mem"/>
       <one-to-onename="stu" property-ref="stuno"/>
    </class>

Many-to-many 双向关联

Course- Student(一门课程可以多个学生学习，一个学生学习多门课程)

Course：publicclass Course {

    private Stringcno;
    private Stringcoursemem;
    private Stringcoursename;
    privateSet
students;}

Course.hbm.xml：

<classname="com.etc.entity.manytomany.Course"table="t_mtom1_course">
       <idname="cno"><generatorclass="uuid"/></id>
       <propertyname="coursemem"/>
       <propertyname="coursename"/>
       <setname="students"table="t_mtom_student_course">
           <keycolumn="courseid"></key>
           <many-to-manyclass="com.etc.entity.manytomany.Student"column="stuid"/>
       </set></class>
Student：

publicclass Student {
    private Stringid;
    privateSet
courses;
    private Stringname;
    privateintage;

}

Student.hbm.xml：

    <classname="com.etc.entity.manytomany.Student"table="t_mtom1_student">
        <idname="id"><generatorclass="uuid"></generator></id>
       <propertyname="name"/>
       <propertyname="age"/>
       <!-- name属性采用实体中变量名称；table属性表示生成的中间表表名；cascade属性表示级联操作   -->
       <setname="courses"table="t_mtom_student_course"cascade="save-update">
           <keycolumn="stuid"></key><!--将此表的主键拿到中间表中的列名为stuid
-->
           <many-to-manyclass="com.etc.entity.manytomany.Course"column="courseid"/>
           <!--com.etc.entity.manytomany.Course对应表的主键拿到中间表中的列名为courseid -->
       </set>
    </class>