Mybatis 一对多(OneToOne)关系映射

http://kinglixing.blog.51cto.com/3421535/709738

关于MyBatis一对多的设置如下:

1.创建数据库脚本

CREATE   TABLE  t_customer(  
  id   int(10)   not   null  auto_increment,  
  address   varchar(120),  
  postcode   varchar(6),  
  sex   varchar(2),  
  cname   varchar(24),  
   primary   key(id)  
)charset="GB2312";  

CREATE   TABLE  t_orders(  
  id   int(10)   not   null  auto_increment,  
  code   varchar(24),  
  customer_id   int(3)   not   null,  
   primary   key(id)  
)charset="GB2312";

ALTER   TABLE  t_orders  
ADD   CONSTRAINT  orders_customer_fk   FOREIGN   KEY  (customer_id)   REFERENCES  t_customer(id)

-- t_orders.customer_id 参照 t_customer.id

 

2.创建实体类(POJO)

Customer.java

package  com.lixing.ibatis.entity.onetomany;  

import  java.io.Serializable;  
import  java.util.List;  

public   class  Customer   implements  Serializable{  
   private   static   final   long  serialVersionUID = 451949797460417653L;  
   private   int  id;  
   private  String address;  
   private  String postcode;  
   private  String sex;  
   private  String cname;  
   private List<Orders> orders;   //一个Customer 对应N多个Orders

   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  String getPostcode() {  
     return  postcode;  
  }  
   public   void  setPostcode(String postcode) {  
     this.postcode = postcode;  
  }  
   public  String getSex() {  
     return  sex;  
  }  
   public   void  setSex(String sex) {  
     this.sex = sex;  
  }  
   public  String getCname() {  
     return  cname;  
  }  
   public   void  setCname(String cname) {  
     this.cname = cname;  
  }  
   public  List<Orders> getOrders() {  
     return  orders;  
  }  
   public   void  setOrders(List<Orders> orders) {  
     this.orders = orders;  
  }  
}  

 

Orders.java

package  com.lixing.ibatis.entity.onetomany;  

import  java.io.Serializable;  

public   class  Orders   implements  Serializable {  
   private   static   final   long  serialVersionUID = 8215977396669780567L;  
   private   int  id;  
   private  String code;  
   private   int  customerId;  
   private Customer customer;  //多个Orders对应一个Customer
    
   public   int  getId() {  
     return  id;  
  }  

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

   public  String getCode() {  
     return  code;  
  }  

   public   void  setCode(String code) {  
     this.code = code;  
  }  

   public   int  getCustomerId() {  
     return  customerId;  
  }  

   public   void  setCustomerId( int  customerId) {  
     this.customerId = customerId;  
  }  

   public  Customer getCustomer() {  
     return  customer;  
  }  

   public   void  setCustomer(Customer customer) {  
     this.customer = customer;  
  }  
}  

 

3.创建Mapper映射接口

CustomerMapper.java

package  com.lixing.ibatis.onetomany.mapper;  

import  com.lixing.ibatis.entity.onetomany.Customer;  

public   interface  CustomerMapper {  
   void  insertCustomer(Customer customer);  
  Customer getCustomer( int  id);  
}  

 

OrdersMapper.java

package  com.lixing.ibatis.onetomany.mapper;  

import  java.util.List;  

import  com.lixing.ibatis.entity.onetomany.Orders;  

public   interface  OrdersMapper {  
   void  insertOrders(Orders orders);  
  List<Orders> getOrders( int  id);    //根据id
  List<Orders> getOrdersById( int  customerId);   //根据customerId获得N多个对象
}  

 

4.创建Mapper XML配置文件

CustomerMapper.xml

<? xml   version ="1.0"   encoding ="UTF-8"   ?>  
<!DOCTYPE mapper    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"    
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">  
< mapper   namespace ="com.lixing.ibatis.onetomany.mapper.CustomerMapper" >  
   < parameterMap   type ="Customer"   id ="parameterCustomerMap" >  
     < parameter   property ="id" />  
     < parameter   property ="address" />  
     < parameter   property ="postcode" />  
     < parameter   property ="sex" />  
     < parameter   property ="cname" />      
   </ parameterMap >  
    
   < insert   id ="insertCustomer"   parameterMap ="parameterCustomerMap" >  
     < selectKey     keyProperty ="id"   resultType ="int"   order ="AFTER" >  
      SELECT @@IDENTITY AS ID  
     </ selectKey >  
    INSERT INTO t_customer(address,postcode,sex,cname)  
    VALUES(#{address},#{postcode},#{sex},#{cname})  
   </ insert >        
    
   < resultMap   type ="Customer"   id ="resultCustomerMap" >  
     < result   property ="id"   column ="id" />  
     < result   property ="address"   column ="address" />  
     < result   property ="postcode"   column ="postcode" />  
     < result   property ="sex"   column ="sex" />  
     < result   property ="cname"   column ="cname" />  
     <collection property="orders" column="id" select="com.lixing.ibatis.onetomany.mapper.OrdersMapper.getOrdersById"/> 
   </ resultMap >  
    
   < select   id ="getCustomer"   resultMap ="resultCustomerMap"   parameterType ="int" >  
    SELECT *  
    FROM t_customer  
    WHERE id=#{id}  
   </ select >          
</ mapper >  

OrderMapper.xml

<? xml   version ="1.0"   encoding ="UTF-8"   ?>  
<!DOCTYPE mapper    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"    
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">  
< mapper   namespace ="com.lixing.ibatis.onetomany.mapper.OrdersMapper" >  
   < parameterMap   type ="Orders"   id ="parameterOrdersMap" >  
     < parameter   property ="id" />  
     < parameter   property ="code" />  
     < parameter   property ="customerId" />  
   </ parameterMap >  
    
   < insert   id ="insertOrders"     parameterMap ="parameterOrdersMap" >  
     < selectKey     keyProperty ="id"   resultType ="int"   order ="AFTER" >  
      SELECT LAST_INSERT_ID() AS ID  
     </ selectKey >  
    INSERT INTO t_orders(code,customer_id)  
    VALUES(#{code},#{customerId})  
   </ insert >    
    
   < resultMap   type ="Orders"   id ="ordersMap" >  
     < result   property ="id"   column ="id" />  
     < result   property ="code"   column ="name" />  
     < result   property ="customerId"   column ="customer_id" />  
     < association   property ="customer"   javaType ="Customer"   column ="customer_id"   select ="com.lixing.ibatis.onetomany.mapper.CustomerMapper.getCustomer" />  
   </ resultMap >    
   < select   id ="getOrders"   resultMap ="ordersMap"   parameterType ="int" >  
    SELECT * FROM t_orders  
    WHERE id=#{id}  
   </ select >  
    
   < select   id ="getOrdersById"   resultMap ="ordersMap"   parameterType ="int" >  
    SELECT * FROM t_orders  
    WHERE customer_id=#{customer_id}  
   </ select >  
    
</ mapper >    

 

5.mybatis-config.xml 文件

<? xml   version ="1.0"   encoding ="UTF-8"   ?>  
<!DOCTYPE configuration  
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"  
        "http://mybatis.org/dtd/mybatis-3-config.dtd">  
< configuration >  
   < settings >  
    <!--  changes from the defaults for testing -->  
     < setting   name ="cacheEnabled"   value ="false"   />  
     < setting   name ="useGeneratedKeys"   value ="true"   />  
     < setting   name ="defaultExecutorType"   value ="REUSE"   />  
   </ settings >  
    
   < typeAliases >  
     < typeAlias   type ="com.lixing.ibatis.entity.onetomany.Customer"   alias ="Customer" />  
     < typeAlias   type ="com.lixing.ibatis.entity.onetomany.Orders"   alias ="Orders" />  
      
   </ typeAliases >  

   < environments   default ="development" >  
     < environment   id ="development" >  
       < transactionManager   type ="JDBC"   />  
       < dataSource   type ="POOLED" >  
         < property   name ="driver"   value ="com.mysql.jdbc.Driver"   />  
         < property   name ="url"   value ="jdbc:mysql://localhost:3306/test"   />  
         < property   name ="username"   value ="root"   />  
         < property   name ="password"   value ="7501857"   />  
       </ dataSource >  
     </ environment >  
   </ environments >  
   < mappers >  
     < mapper   resource ="com/lixing/ibatis/onetomany/mapper/CustomerMapper.xml" />  
     < mapper   resource ="com/lixing/ibatis/onetomany/mapper/OrdersMapper.xml" />  
   </ mappers >  
</ configuration >  

 

6.创建测试类

package  com.lixing.ibatis.test;  

import  java.util.Iterator;  
import  java.util.List;  

import  org.apache.ibatis.session.SqlSession;  
import  org.apache.ibatis.session.SqlSessionFactory;  
import  org.junit.After;  
import  org.junit.Before;  
import  org.junit.Test;  

import  com.lixing.ibatis.entity.onetomany.Customer;  
import  com.lixing.ibatis.entity.onetomany.Orders;  
import  com.lixing.ibatis.onetomany.mapper.CustomerMapper;  
import  com.lixing.ibatis.onetomany.mapper.OrdersMapper;  
import  com.lixing.ibatis.util.MyBatisUtil;  


public   class  OrdersMapperTest {  
   private  SqlSessionFactory sqlSessionFactory= null;  
   private  SqlSession session= null;  
    
  @Before  
   public   void  before(){  
    sqlSessionFactory=MyBatisUtil.getInstance();  
    session=sqlSessionFactory.openSession();  
  }  
    
  @Test  
   public   void  testInsertOrders(){  
    Orders orders= new  Orders();  
    orders.setCode( "code__1");  
    orders.setCustomerId(1);  
      
    OrdersMapper ordersMapper=session.getMapper(OrdersMapper. class);  
    ordersMapper.insertOrders(orders);  
    session.commit();      
  }  
    
  @Test  
   public   void  testInsertCustomerOneToMany(){  
    Customer customer= new  Customer();  
    customer.setCname( "Lixing5");  
    customer.setPostcode( "518105");  
    customer.setSex( "男");  
    customer.setAddress( "广东省深圳市5");  
      
    CustomerMapper customerMapper=session.getMapper(CustomerMapper. class);  
    customerMapper.insertCustomer(customer);  
    System.out.println(customer.getId());  
      
    Orders orders1= new  Orders();  
    orders1.setCode( "code__5_1");  
    orders1.setCustomerId(customer.getId());  
      
    Orders orders2= new  Orders();  
    orders2.setCode( "code__5_2");  
    orders2.setCustomerId(customer.getId());  
      
    Orders orders3= new  Orders();  
    orders3.setCode( "code__5_3");  
    orders3.setCustomerId(customer.getId());  
      
    OrdersMapper ordersMapper=session.getMapper(OrdersMapper. class);  
    ordersMapper.insertOrders(orders1);  
    ordersMapper.insertOrders(orders2);  
    ordersMapper.insertOrders(orders3);  
      
    session.commit();    
  } 
    
     
  @Test  
   public   void  testGetOrdersManyToOne(){  
    OrdersMapper ordersMapper=session.getMapper(OrdersMapper. class);  
    List<Orders> list=ordersMapper.getOrdersById(5);  
     for( int  i=0;i<list.size();i++){  
      Orders orders=list.get(i);  
      Customer customer=orders.getCustomer();  
      System.out.println(orders.getId()+ "\t"+orders.getCode()+ "\t"+orders.getCustomerId());  
      System.out.println( "\t \t--:"+customer.getId()+ "\t"+customer.getCname());  
    }      
    session.commit();  
  }  
    
    
  @Test  
   public   void  testGetCustomerOneToMany(){  
    CustomerMapper customerMapper=session.getMapper(CustomerMapper. class);  
    Customer customer=customerMapper.getCustomer(5);  
    List<Orders> orders=customer.getOrders();  
    System.out.println(customer.getId()+ "\t"+customer.getCname()+ "\t"+customer.getPostcode()+ "\t"+customer.getAddress());  
     for( int  i=0;i<orders.size();i++){  
      Orders order=orders.get(i);  
      System.out.println( "\t \t --:"+order.getId()+ "\t"+order.getCode()+ "\t"+order.getCustomerId());  
    }  
    session.commit();  
  }  
    
  @After  
   public   void  after(){  
    session.close();  
  }  
}