本文介紹了association的基本使用方法下面就是具體的程式碼

Junit程式碼

	@Test
	public void test05() throws IOException{
		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
		SqlSession openSession = sqlSessionFactory.openSession();
		try{
			EmployeeMapperPlus mapper = openSession.getMapper(EmployeeMapperPlus.class);
			Employee empAndDept = mapper.getEmpAndDept(1);
			System.out.println(empAndDept);
			System.out.println(empAndDept.getDept());
		}finally{
			openSession.close();
		}
	}
	
 

EmployeeMapperPlus

package com.atguigu.mybatis.dao;

import java.util.List;

import com.atguigu.mybatis.bean.Employee;

public interface EmployeeMapperPlus {
	
	public Employee getEmpById(Integer id);
	
	public Employee getEmpAndDept(Integer id);
	
	public Employee getEmpByIdStep(Integer id);
	
	public List<Employee> getEmpsByDeptId(Integer deptId);

}
 

xml

	<!--
		使用association定義關聯的單個物件的封裝規則；
	 -->
	<resultMap type="com.atguigu.mybatis.bean.Employee" id="MyDifEmp2">
		<id column="id" property="id"/>
		<result column="last_name" property="lastName"/>
		<result column="gender" property="gender"/>

		<!--  association可以指定聯合的javaBean物件
		property="dept"：指定哪個屬性是聯合的物件
		javaType:指定這個屬性物件的型別[不能省略]
		-->
		<association property="dept" javaType="com.atguigu.mybatis.bean.Department">
			<id column="did" property="id"/>
			<result column="dept_name" property="departmentName"/>
		</association>
	</resultMap>
	<!--  public Employee getEmpAndDept(Integer id);-->
	<select id="getEmpAndDept" resultMap="MyDifEmp">
		SELECT e.id id,e.last_name last_name,e.gender gender,e.d_id d_id,
		d.id did,d.dept_name dept_name FROM tbl_employee e,tbl_dept d
		WHERE e.d_id=d.id AND e.id=#{id}
	</select>
 

請注意xml中的註釋