hibernate Dao层实现

最新推荐文章于 2018-07-19 14:57:00 发布

yin1004981045

最新推荐文章于 2018-07-19 14:57:00 发布

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本文链接：https://blog.youkuaiyun.com/yin1004981045/article/details/80708605

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本文详细介绍了 Hibernate 中 Dao 层的实现，包括继承映射、多对多、一对多和一对一的关系映射。通过示例代码展示了 People、Student、Teacher、Room 和 User 类在 hbm.xml 文件及 Java 对象间的映射配置，同时提供了增删查改的基础模板。

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1.继承映射

People.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- 继承映射 -->
<hibernate-mapping package="com.vo.extend">
	<class name="People" table="people">
		<id name="id" column="id">
			<generator class="identity" />
		</id>
		<discriminator column="type" />
		<subclass name="Teacher" discriminator-value="T" >
			<property name="tname" column="tname" />
		</subclass>
		<subclass name="Student" discriminator-value="S" >
			<property name="sname" column="sname" />
		</subclass>
	</class>
</hibernate-mapping>

People.java

public class People {
	private int id;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}
}

Student.java

public class Student extends People {
	private String sname;

	public String getSname() {
		return sname;
	}

	public void setSname(String sname) {
		this.sname = sname;
	}
}

Teacher.java

public class Teacher extends People {
	private String tname;

	public String getTname() {
		return tname;
	}

	public void setTname(String tname) {
		this.tname = tname;
	}
}

2.多对多映射

Room.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.vo.manytomany">
	<class name="Room" table="room">
		<id name="room_id" column=&

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