ibatis入门尝试5 一对多（OneToMany）关联

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

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

//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

<?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

<?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

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

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());
}