Hibernate 的关系与配置

最新推荐文章于 2024-08-05 14:22:58 发布

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hibernate 同时被 3 个专栏收录

41 篇文章

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mapping

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subclass

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1.单向 N:1
例如:一个地方有多个人住.
(在1 的一端进行配置,每个同学记住老师,比老师记住每个同学简单.效率高)


public class Address {
	private Integer addressid;
	private String addressDetail;

        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	private Address address;  //单向(N:1)  反过来(1:1) 
	//set  get...
}



#主表
DROP TABLE IF EXISTS mytest.address;
CREATE TABLE mytest.address
(
aid         INTEGER NOT NULL,
addressdesc VARCHAR (400),
PRIMARY KEY (aid)
);

#子表
DROP TABLE IF EXISTS mytest.person;

CREATE TABLE mytest.person
(
pid        INTEGER NOT NULL,
name       VARCHAR (50) NOT NULL,
age        TINYINT NOT NULL DEFAULT 0,
address_id INTEGER,
PRIMARY KEY (pid),
KEY address_id (address_id),
CONSTRAINT person_ibfk_1 FOREIGN KEY (address_id) REFERENCES address (aid)
);

   <!--方式1.没有中间关联表(没有中间表)-->
   <!--在Person.hbm.xml的配置文件中加入 many:Person  one:Address -->
   <many-to-one name="address" cascade="all" class="Address" column="address_id"/>

   <!--方式2.有中间关联表(有中间表:person_address(person_id,address_id))-->
   <!--在Person.hbm.xml的配置文件中加入 many:Person  one:Address -->
   <join table="person_address">
			<key column="person_id"/>
			<many-to-one name="address" cascade="all" class="Address" column="address_id"/>
   </join>

2.单向 1:1


public class Address {
	private Integer addressid;
	private String addressDetail;

        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	private Address address;  //单向(N:1)  反过来(1:1) 
	//set  get...
}

基于外键的单向1:1

   <!--方式1.没有中间关联表(没有中间表)-->
   <!--在Person.hbm.xml的配置文件中加入 many:Person  one:Address -->
   <many-to-one name="address" unique="true" cascade="all"  class="Address" column="address_id"/>

  
   <!--方式2.有中间关联表(有中间表:person_address(person_id,address_id))-->
   <!--在Person.hbm.xml的配置文件中加入 many:Person  one:Address -->
   <join table="person_address">
			<key column="person_id"/>
			<many-to-one name="address" unique="true" cascade="all" class="Address" column="address_id"/>
   </join>

基于主键的单向 1:1

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.Person" table="PERSON">
		<id name="id" type="java.lang.Integer">
			<column name="ID" />
			<!-- <generator class="native" /> -->
			<generator class="foreign">
				<!--通过property 指定 映射的主键为 自己的属性  address这个对象  -->
				<param name="property">address</param>
			</generator>
		</id> 
		<property name="name" type="java.lang.String">
			<column name="NAME" />
		</property>
		<property name="age" type="int">
			<column name="AGE" />
		</property>
			
		<!--单向 主键关联(即,该表不能自己生成主键 ,只能引用其他表的主键 比如下面,是引用 Address表 主键 -->
		<one-to-one name="address"/>		
	</class>
</hibernate-mapping>

3.单向 1:N
例如:一个人有多个住的地址(土豪啦)


public class Address {
	private Integer addressid;
	private String addressDetail;

        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	//如果一个人有多个地址,而一个地址 又像上面,有多个人,这样就形成了  N:N  所以 1:N 包含了(N:N)
	private Set<Address> addresses=new HashSet<Address>();//1:N(包含了 N:N)
	
	//set  get...
}

     <!--方式一:没有中间表-->
     <!--在Person.hbm.xml中配置-->
<set name="addresses">
		<key column="person_id"/>
		<one-to-many class="Address" not-found="ignore"/>
</set>

     <!--方式二:有中间表(person_address(person_id,address_id))-->
     <!--还是在Person.hbm.xml中配置-->
<set name="addresses" table="person_addesses" cascade="all">
			<key column="person_id"/>
			<many-to-many class="Address" column="address_id" unique="true"/>
</set>

4.单向 N:N
单向N:N的关联,必须使用中间表


public class Address {
	private Integer addressid;
	private String addressDetail;

        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	//如果一个人有多个地址,而一个地址 又像上面,有多个人,这样就形成了  N:N  所以 1:N 包含了(N:N)
	private Set<Address> addresses=new HashSet<Address>();//1:N(包含了 N:N)
	
	//set  get...
}

     <!--方式二:有中间表(person_address(person_id,address_id))-->
     <!--还是在Person.hbm.xml中配置-->
<set name="addresses" table="person_addesses" cascade="all">
			<key column="person_id"/>
			<many-to-many class="Address" column="address_id"/>
</set>

5.双向 1:N


public class Address {
	private Integer addressid;
	private String addressDetail;

        private Person person;
        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	private Set<Address> addresses=new HashSet<Address>();
	
	//set  get...
}

     <!--方式一:没有中间表-->
     <!--在Person.hbm.xml中配置-->    
     <set name="addresses" inverse="true">
			<key column="person_id"/>
			<one-to-many class="Address"/>
     </set>
     <!--在Address.hbm.xml中配置-->   
     <many-to-one name="person" class="Person" column="person_id" not-null="true"/>

     <!--方式二:有中间表(person_address(person_id,address_id))-->
     <!--在Person.hbm.xml中配置-->
<set name="addresses" inverse="true" table="person_address">
			<key column="person_id"/>
			<many-to-many column="address_id" class="Address" unique="true"/>
		</set>
     <!--在Address.hbm.xml中配置-->  
<join table="person_address">
			<key column="address_id"/>
			<many-to-one name="person" column="person_id" not-null="true"></many-to-one>
		</join>

</set>

6.双向 N:N
双向N:N的关联,必须使用中间表


public class Address {
	private Integer addressid;
	private String addressDetail;

        private Set<Person> persons=new HashSet<Person>();
        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	private Set<Address> addresses=new HashSet<Address>();
	
	//set  get...
}

 <!--在Person.hbm.xml中配置-->    
<set name="addresses" inverse="true" table="person_address">
			<key column="person_id"/>
			<many-to-many column="address_id" class="Address"/>
		</set>

 <!--在Address.hbm.xml中配置-->  
<set name="persons" table="peson_addresses">
			<key column="address_id"/>
			<many-to-many column="person_id" class="Person"/>
		</set>

6.双向 1:1


public class Address {
	private Integer addressid;
	private String addressDetail;
        private Person  person;
        //set get ...
}

public class Person {

	private Integer id;
	private String name;
	private int age;
	
	private Address address;  
	//set  get...
}

//基于外键的双向1:1

      <!--方式1:没有关联表-->
      <!--在Person.hbm.xml中配置-->  
      <one-to-one name="address" property/>
       
      <!--在Address.hbm.xml中配置-->  
      <many-to-one name="person" class="Person" unique="true" column="person_id" not-null="true"/>
       
      <!--方式2:有关联表-->
      <!--在Person.hbm.xml中配置-->
<join table="person_address" inverse="true">
			<key column="person_id" unique="true"/>
			<many-to-one name="address" unique="true" class="Address" column="address_id"/>
		</join>

       <!--在Address.hbm.xml中配置-->  
        <join table="person_address" optional="true">
			<key column="address_id" unique="true"/>
			<many-to-one name="person" unique="true" column="person_id" not-null="true"/>
		</join>

//基于主键的双向1:1

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.Person" table="PERSON">
		<id name="id" type="java.lang.Integer">
			<column name="ID" />
			<!-- <generator class="native" /> -->
			<generator class="foreign">
				<!--通过property 指定 映射的主键为 自己的属性  address这个对象  -->
				<param name="property">address</param>
			</generator>
		</id> 
		<property name="name" type="java.lang.String">
			<column name="NAME" />
		</property>
		<property name="age" type="int">
			<column name="AGE" />
		</property>
			
		<!--单向 主键关联(即,该表不能自己生成主键 ,只能引用其他表的主键 比如下面,是引用 Address表 主键 -->
		<one-to-one name="address"/>		
	</class>
</hibernate-mapping>


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.Address" table="ADDRESS">
		<id name="id" type="java.lang.Integer">
			<column name="ID" />
			<generator class="native" />
		</id> 
		<property name="addressDetail" type="java.lang.String">
			<column name="ADDRESSDETAIL" />
		</property>
		
                <one-to-one name="person"/>
		
	</class>
</hibernate-mapping>


这中配置,可以互换 ,现在是person的主键,有address 生成 
反过来也可以.

7.组建属性包含关联实体


//不是持久化类
public class Address {  
    private Integer addressid;  
    private String addressDetail;  
    private Set<School> schools=new HashSet<School>();
        //set get ...  
}  
  
public class School {
	private Integer schoolId;
	private String schoolname;
//get set
}

public class Person {  
  
    private Integer id;  
    private String name;  
    private int age;  
      
    private Address address;  //单向(N:1)  反过来(1:1)   
    //set  get...  
}

//在person中进行配置
 <!--Person 中 的address是组件 不是持久化类  -->
		<component name="address" class="Address">
			<parent name="person"/> <!--Address 类中的pseron类  -->
			<property name="addressDetail"/>
			<set name="schools">
				<key column="address_id"/>
				<one-to-many class="School"/>
			</set>
		</component>

8.复合主键的关联关系



public class Person {

	//多列 联合组件
	private String first;
	private String last;
	
	private String name;
	private int age;

	private Set<Address> addresses=new HashSet<Address>();//1:N(包含了 N:N)

//get set	
}

public class Address {
	private Integer id;
	private String addressDetail;
	private Person person;
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.Person" table="PERSON">
		<composite-id>
			<key-property name="first" type="string"/>
			<key-property name="last" type="string"/>
		</composite-id>

		<property name="name" type="java.lang.String">
			<column name="NAME" />
		</property>
		<property name="age" type="int">
			<column name="AGE" />
		</property>

                <set name="addresses" inverse="true" cascade="all">
			<key>
                            <column name="fisrt"/>                                                                  
                            <column name="last"/>
                         </key>
			<one-to-many class="Address"/>
		</set>	
	</class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.Address" table="PERSON">
		<id name="id" type="java.lang.Integer">
			<column name="ID" />
			<generator class="native" />
		</id> 
		<property name="addressDetail" type="java.lang.String">
			<column name="ADDRESSDETAIL" />
		</property>
                <many-to-one name="person" class="Person" not-null="true">
                             <column name="fisrt"/>                                                                  
                            <column name="last"/>

                </many-to-one>
	</class>
</hibernate-mapping>

9.复合主键的成员属性为关联实体


public class Order {

	private Integer orderId;
	private Date orderDate;
	private Set<OrderItem> items=new HashSet<OrderItem>();
	//get set
}

public class OrderItem {
	private Order order;
	private Product product;
	private int count;
//get set
}
public class Product {
	private Integer productId;
	private String name;
//get set
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2013-12-2 22:01:23 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
	<class name="com.crazyit.app.domain.mapping.OrderItem" table="order_item_info">
		
		<composite-id>
			<key-many-to-one name="product" class="Product" column="product_id"/>
			<key-many-to-one name="order" class="Order" column="order_id"/>
			<key-property name="count" type="int"/>
		</composite-id>
	</class>
</hibernate-mapping>

10.采用subclass 进行继承映射


public class Person {

	private Integer id;
	private String name;
	private char gender;
	
	private Address address;
//get set
	
}

public class Address { 
 
	private String detail;
	private String zip;
	private String country;
//get set 
}


public class Employee extends Person {

	private String title;
	private double salary;
	private Set<Customer> customers=new HashSet<Customer>();
	private Manager manager;
//get set
}

public class Customer extends Person {

	private String commnets;
	private Employee employee;
//get set
}


public class Manager extends Employee {

	private String department;
	private Set<Employee> employees=new HashSet<Employee>();
//get set	
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2014-1-12 13:35:14 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="com.crazyit.app.domain.extenr.Person" table="PERSON" discriminator-value="普通人">
        <id name="id" type="java.lang.Integer" access="field">
            <column name="ID" />
            <generator class="assigned" />
        </id>
        <discriminator column="wawa" type="string"/>
        <property name="name" type="java.lang.String" access="field">
            <column name="NAME" />
        </property>
        <property name="gender" type="char" access="field">
            <column name="GENDER" />
        </property>
        <component name="address">
        	<property name="detail"/>
        	<property name="zip"/>
        	<property name="country"/>
        </component>
       
       <subclass name="Employee" discriminator-value="雇员">
       		<property name="title"/>
       		<property name="salary"/>
       		<many-to-one name="manager" column="manager_id"/>
       		<set name="customer" inverse="true">
       			<key column="employee_id"/>
       			<one-to-many class="Customer"/>
       		</set>
       		<subclass name="Manager" discriminator-value="经理">
       			<property name="department"/>
       			<set name="employees" inverse="false">
       				<key column="manager_id"/>
       				<one-to-many class="Employee"/>
       			</set>
       		</subclass>
       		
       </subclass>
       <subclass name="Customer" discriminator-value="顾客">
       		<property name="comments"/>
       		<many-to-one name="employee" column="employee_id"/>
       </subclass>
       <!-- 采用这中配置的缺点:定义的子类字段不能有非空约束 否则保存其他子类的 时候出现冲突,
       				优点:不用采用多表连接查询,性能比较好
           父类和子类的所有属性都在一个表中
        -->
    </class>
</hibernate-mapping>

11.采用joined-subclass 进行继承映射

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2014-1-12 13:35:14 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="com.crazyit.app.domain.extenr.Person" table="PERSON" discriminator-value="普通人">
        <id name="id" type="java.lang.Integer" access="field">
            <column name="ID" />
            <generator class="assigned" />
        </id>
        <discriminator column="wawa" type="string"/>
        <property name="name" type="java.lang.String" access="field">
            <column name="NAME" />
        </property>
        <property name="gender" type="char" access="field">
            <column name="GENDER" />
        </property>
        <component name="address">
        	<property name="detail"/>
        	<property name="zip"/>
        	<property name="country"/>
        </component>
       <joined-subclass name="Employee">
       	   <key column="employee_id"/>
       	   <property name="title" not-null="true"/>
       	   <property name="salary" not-null="true"/>
       	   <many-to-one name="manager" column="manager_id"/>
       	   <set name="customers" inverse="true">
       	   		<key column="employee_id"/>
       	   		<one-to-many class="Customer"/>
       	   </set>
       	   <joined-subclass name="Manager">
       	   		<key column="manager_id"/>
       	   		<property name="department"/>
       	   		<set name="employees" inverse="true">
       	   			<key column="manager_id"/>
       	   			<one-to-many class="Employee"/>
       	   		</set>
       	   </joined-subclass>
       </joined-subclass>
       
       <joined-subclass name="Customer">
       		<key column="customer_id"/>
       		<property name="commnets" not-null="true"/>
       		<many-to-one name="employee" column="employee_id" not-null="true"/>
       </joined-subclass>
    </class>
</hibernate-mapping>

<!--这中配置特点是:子类的特性保存在子表中,共性保存在父类中,子类的属性可以加入非空约束了-->

21.采用union-subclass 进行继承映射

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2014-1-12 13:35:14 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="com.crazyit.app.domain.extenr.Person" table="PERSON" discriminator-value="普通人">
        <id name="id" type="java.lang.Integer" access="field">
            <column name="ID" />
            <generator class="assigned" />
        </id>
        <discriminator column="wawa" type="string"/>
        <property name="name" type="java.lang.String" access="field">
            <column name="NAME" />
        </property>
        <property name="gender" type="char" access="field">
            <column name="GENDER" />
        </property>
        <component name="address">
        	<property name="detail"/>
        	<property name="zip"/>
        	<property name="country"/>
        </component>
       <union-subclass name="Employee" table="employee_inf">
       		<property name="title" not-null="true"/>
       		<property name="salary" not-null="true"/>
       		<many-to-one name="manager" column="manager_id"/>
       		<set name="customers" inverse="true">
       			<key column="employee_id"/>
       			<one-to-many class="Customer"/>
       		</set>
       		<union-subclass name="Manager" table="manager_inf">
       			<property name="department"/>
       			<set name="employees" inverse="true">
       				<key column="manage_id"/>
       				<one-to-many class="Employee"/>
       			</set>
       		</union-subclass>
       </union-subclass>
       <union-subclass name="Customer" table="customer_inf">
       	<property name="commnents" not-null="true"/>
       	<many-to-one name="employee" column="employee_id" not-null="true"/>
       </union-subclass>
    </class>
</hibernate-mapping>

<!--
  子类的特性和共性,在子表中都会存在,和 joined-subclass的最他区别.
 使用union-subclass 持久化的主键生成方式不能是 identity ,sequence,native.
 -->