文章目錄

• • • 1、創(chuàng)建表結(jié)構(gòu)
    • 2、EmployeeMapper接口
    • 3、EmployeeMapper.xml
    • 4、Test

1、創(chuàng)建表結(jié)構(gòu)

CREATE TABLE `mybatis`.`dept` (`id` INT NOT NULL ,`dept_name` VARCHAR(45) NULL ,PRIMARY KEY (`id`) );alter table employee add d_id INT(45);INSERT INTO `mybatis`.`dept` (`id`, `dept_name`) VALUES ('1', '開發(fā)部'); INSERT INTO `mybatis`.`dept` (`id`, `dept_name`) VALUES ('2', '測(cè)試部');

2、EmployeeMapper接口

package com.mi.dao;import com.mi.pojo.Employee; import org.apache.ibatis.annotations.MapKey; import org.apache.ibatis.annotations.Param;import java.util.List; import java.util.Map;public interface EmployeeMapper {//查詢員工及部門public Employee getEmpAndDept(Integer id); }

3、EmployeeMapper.xml

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <!--指定為接口的全類名--> <mapper namespace="com.mi.dao.EmployeeMapper"><!--聯(lián)合查詢，級(jí)聯(lián)屬性封裝結(jié)果集--><resultMap id="myEmpAndEmp" type="com.mi.pojo.Employee"><id column="id" property="id"/><result column="last_name" property="lastName"/><result column="gender" property="gender"/><result column="d_id" property="dept.id"/><result column="dept_name" property="dept.deptName"/></resultMap><!--關(guān)聯(lián)查詢員工及部門--><select id="getEmpAndDept" resultMap="myEmpAndEmp">select e.id,e.last_name, e.gender,d.id d_id,d.dept_name dept_namefrom employee e ,dept dwhere e.d_id = d.id and e.id = #{id}</select> </mapper>

4、Test

@Testpublic void getEmpAndDept() throws IOException {//1、獲取SqlSessionFactory對(duì)象SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();//2、獲取Sqlsesion對(duì)象SqlSession sqlSession = sqlSessionFactory.openSession();try {//3、獲取接口的實(shí)現(xiàn)類對(duì)象//會(huì)為接口自動(dòng)創(chuàng)建一個(gè)代理對(duì)象，代理對(duì)象去執(zhí)行增刪改查方法EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);Employee employee = mapper.getEmpAndDept(3);System.out.println(employee);System.out.println(employee.getDept());}finally {sqlSession.close();}}

總結(jié)

以上是生活随笔為你收集整理的13、mybatis多表关联查询级联属性的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。