Hibernate學習7—Hibernate 映射繼承

標籤：pac   images   port   e30   技術   system   setname   pre   student   

需求：學生有很多照片，分為生活照和工作照；

第一節：每個具體類對應一個表　　　　　　　　　　　　　　　　　　　　　　　　

Student.java:

package com.cy.model;import java.util.Set;public class Student {    private int id;    private String name;    private Set<Image> images;        public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public Set<Image> getImages() {        return images;    }    public void setImages(Set<Image> images) {        this.images = images;    }            }

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抽象類別Image.java:

package com.cy.model;public abstract class Image {    private int id;    private String imageName;    private Student student;            public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getImageName() {        return imageName;    }    public void setImageName(String imageName) {        this.imageName = imageName;    }    public Student getStudent() {        return student;    }    public void setStudent(Student student) {        this.student = student;    }        }

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生活照LifeImage.java:

package com.cy.model;public class LifeImage extends Image{}

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工作照WorkImage.java:

package com.cy.model;public class WorkImage extends Image{}

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Student.hbm.xml:

<hibernate-mapping package="com.cy.model">    <class name="Student" table="t_student">        <id name="id" column="stuId">            <generator class="native"></generator>        </id>        <property name="name" column="stuName"></property>    </class></hibernate-mapping>

LifeImage.hbm.xml:

<hibernate-mapping package="com.cy.model">    <class name="LifeImage" table="t_lifeImage">        <id name="id" column="lifeImageId">            <generator class="native"></generator>        </id>        <property name="imageName" column="imageName"></property>                <many-to-one name="student" column="stuId" class="com.cy.model.Student"></many-to-one>    </class></hibernate-mapping>

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WorkImage.hbm.xml:

<hibernate-mapping package="com.cy.model">    <class name="WorkImage" table="t_workImage">        <id name="id" column="workImageId">            <generator class="native"></generator>        </id>        <property name="imageName" column="imageName"></property>                <many-to-one name="student" column="stuId" class="com.cy.model.Student"></many-to-one>    </class></hibernate-mapping>

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測試代碼StudentTest.java:

    @Test    public void testGetAllImages(){        List<Image> imageList = new ArrayList<Image>();        int stuId = 1;        List<Image> lifeImageList = (List<Image>)session.createQuery("from LifeImage l where l.student.id = " + stuId).list();        imageList.addAll(lifeImageList);        List<Image> workImageList = (List<Image>)session.createQuery("from WorkImage w where w.student.id = " + stuId).list();        imageList.addAll(workImageList);        for(Image image: imageList){            System.out.println(image.getImageName());        }            }

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三個表的關聯關係：

t_lifeimage表結構：

t_lifeimage表資料：

t_workimage表資料：

 

 

第二節：根類對應一個表　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

 

Hibernate學習7—Hibernate 映射繼承