mybatis

其实一对多关联跟我们之前的一对一关联在实现上没有区别，这里只是简单举例子说明一下。
我们以客户对订单为例。
首先创建数据库
Java代码  收藏代码

    CREATE TABLE `customer` (  
      `id` int(11) NOT NULL auto_increment,  
      `name` varchar(50) default NULL,  
      `address` varchar(200) default NULL,  
      PRIMARY KEY  (`id`)  
    )  
    CREATE TABLE `orders` (  
      `id` int(11) NOT NULL auto_increment,  
      `code` varchar(50) default NULL,  
      `customerid` int(11) default NULL,  
      PRIMARY KEY  (`id`),  
      KEY `sda` (`customerid`),  
      CONSTRAINT `sda` FOREIGN KEY (`customerid`) REFERENCES `customer` (`id`) ON DELETE CASCADE  
    )  


订单通过一个外建与客户表关联
实体Bean
Java代码  收藏代码

    //客户类  
    public class Customer {  
        private int id;  
        private String name;  
        private String address;  
        private List<Orders> orders;  
        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 String getAddress() {  
            return address;  
        }  
        public void setAddress(String address) {  
            this.address = address;  
        }  
        public List<Orders> getOrders() {  
            return orders;  
        }  
        public void setOrders(List<Orders> orders) {  
            this.orders = orders;  
        }  
          
    }  
    //订单类  
    public class Orders {  
        private int id;  
        private String code;  
        private int customerid;  
          
        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;  
        }  
    }  



下面是对应的配置文件
客户实体的配置文件
Java代码  收藏代码

    <?xml version="1.0" encoding="UTF-8"?>  
    <!DOCTYPE sqlMap  
    PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"  
    "http://ibatis.apache.org/dtd/sql-map-2.dtd">  
    <sqlMap namespace="customer">  
    <typeAlias alias="customerVO" type="com.bean.onetomany.Customer"/>  
    <parameterMap class="customerVO" id="customerVOmp">  
        <parameter property="id" jdbcType="int"/>  
        <parameter property="name" jdbcType="varchar"/>  
        <parameter property="address" jdbcType="varchar"/>  
    </parameterMap>  
    <insert id="createCustomer" parameterMap="customerVOmp">  
        <selectKey keyProperty="id" type="post" resultClass="int">  
            select @@IDENTITY as value  
        </selectKey>  
        insert into customer(id,name,address) values(?,?,?)  
    </insert>  
    <resultMap class="customerVO" id="getCustomer">  
        <result column="id" property="id" jdbcType="int"/>  
        <result column="name" property="name" jdbcType="varchar"/>  
        <result column="address" property="address" jdbcType="varchar"/>  
        <result property="orders" column="id" select="orders.getOrdersByCid"/>  
    </resultMap>  
    <select id="getCustomerByName" parameterClass="java.lang.String" resultMap="getCustomer">  
        select * from customer where name=#value#  
    </select>  
    </sqlMap>  


订单实体的配置文件
Java代码  收藏代码

    <?xml version="1.0" encoding="UTF-8"?>  
    <!DOCTYPE sqlMap  
    PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"  
    "http://ibatis.apache.org/dtd/sql-map-2.dtd">  
    <sqlMap namespace="orders">  
    <typeAlias alias="ordersVO" type="com.bean.onetomany.Orders"/>  
    <parameterMap class="ordersVO" id="ordersVOmp">  
        <parameter property="id" jdbcType="int"/>  
        <parameter property="code" jdbcType="varchar"/>  
        <parameter property="customerid" jdbcType="int"/>  
    </parameterMap>  
    <insert id="createOrders" parameterMap="ordersVOmp">  
        <selectKey>  
        select @@IDENTITY as value  
        </selectKey>  
        insert into orders(id,code,customerid) values(?,?,?)  
    </insert>  
    <select id="getOrdersByCid" parameterClass="int" resultClass="ordersVO">  
        select * from orders where customerid = #value#  
    </select>  
    </sqlMap>  



测试方法新增操作 与onetoone的新增没有本质区别
预习了一下之前的批次处理的方式
Java代码  收藏代码

    Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");  
    SqlMapClient sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);  
      
    Customer c1 = new Customer();  
    c1.setName("customer1");  
    c1.setAddress("c1_address1");  
      
    sqlMap.startTransaction();  
    sqlMap.insert("customer.createCustomer", c1);  
    sqlMap.startBatch();  
    for(int i = 0;i<10;i++){  
        Orders o = new Orders();  
        o.setCustomerid(c1.getId());  
        o.setCode("code_c1 "+i);  
        sqlMap.insert("orders.createOrders", o);  
    }  
    sqlMap.executeBatch();  
    sqlMap.commitTransaction();  



查询方法 实现了customer 到orders 的一对多查询
Java代码  收藏代码

    Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");  
              
    SqlMapClient sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);  
          
    Customer customer = (Customer)sqlMap.queryForObject("customer.getCustomerByName", "customer1");  
    System.out.println(customer.getAddress());  
    List<Orders> orders = customer.getOrders();  
    for(int i = 0 ; i<orders.size();i++){  
        Orders o = orders.get(i);  
        System.out.println(o.getCode());  
    }