ORM映射详解-优快云博客

1、双向一对一外键关联

package org.lazyzhong.model;

public class User {
	private int id;
	private String name;
	private Address address;
	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 Address getAddress() {
		return address;
	}
	public void setAddress(Address address) {
		this.address = address;
	}
	public User() {
		super();
	}
}

package org.lazyzhong.model;

public class Address {
	private int id;
	private String address;
	private User user;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	public User getUser() {
		return user;
	}
	public void setUser(User user) {
		this.user = user;
	}
	public Address() {
		super();
	}
}

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="User" table="user">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
		<property name="name" type="string" length="10" />
		<many-to-one name="address" column="addressid" unique="true" />
    </class>
</hibernate-mapping>

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="Address" table="address">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
        <property name="address" type="string" length="20" />
        <one-to-one name="user" class="User" />
        
    </class>
</hibernate-mapping>

2、双向一对多外键关联：

package org.lazyzhong.model;

import java.util.List;

public class User {
	private int id;
	private String name;
	private List<Address> addresses;
	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 List<Address> getAddresses() {
		return addresses;
	}
	public void setAddresses(List<Address> addresses) {
		this.addresses = addresses;
	}
	public User() {
		super();
	}
}

package org.lazyzhong.model;

public class Address {
	private int id;
	private String address;
	private User user;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	public User getUser() {
		return user;
	}
	public void setUser(User user) {
		this.user = user;
	}
	public Address() {
		super();
	}
}

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="User" table="user">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
		<property name="name" type="string" length="10" />
		
		<bag name="addresses" cascade="all">
			<!-- 指定外键名。。 -->
			<key column="userid" />
			<one-to-many class="Address" />
		</bag>
    </class>
</hibernate-mapping>

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="Address" table="address">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
        <property name="address" type="string" length="20" />
        <many-to-one name="user" class="User" cascade="all">
        	<column name="userid" />
        </many-to-one>
    </class>
</hibernate-mapping>

3、双向一对多连接表关联：

实体类和上面的一致。。。

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="User" table="user">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
		<property name="name" type="string" length="10" />
		
		<bag name="addresses" cascade="all" table="jointab">
			<!-- 指定外键名。。 -->
			<key column="userid" />
			<many-to-many unique="true" class="Address" column="addressid" />
		</bag>
		
    </class>
</hibernate-mapping>

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="Address" table="address">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
        <property name="address" type="string" length="20" />
        
        <join table="jointab" inverse="true">
        <key column="addressid" />
        <many-to-one name="user" class="User" cascade="all" column="userid" />
        </join>
    </class>
</hibernate-mapping>

4、多对多双向关联

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="User" table="user">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
		<property name="name" type="string" length="10" />
		
		<bag name="addresses" cascade="all" table="jt">
			<key column="userid" />
			<many-to-many class="Address" column="addressid" />
		</bag>
		
    </class>
</hibernate-mapping>

<?xml version="1.0" encoding="GBK"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="org.lazyzhong.model">
    <class name="Address" table="address">
		<id	name="id" type="int">
			<generator class="identity"/>
		</id>
        <property name="address" type="string" length="20" />
        
		<bag name="users" cascade="all" table="jt">
			<key column="addressid" />
			<many-to-many class="Address" column="userid"/>
		</bag>
		
    </class>
</hibernate-mapping>

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