MyBatis 中两表关联查询MYSQL (14)

MyBatis 中两表关联查询MYSQL

1、创建数据库表语句

2、插入测试数据

 

 3、pom文件内容

<?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>
    <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://127.0.0.1:3306/mybatis01"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- jack.zhao 加载映射文件 -->
        <mapper resource="com/mybatis03/mapper/personMapper.xml"/>
        <mapper resource="com/mybatis03/mapper/TeacherMapper.xml"/>
    </mappers>
</configuration>

4、实体类

4.1教师表对应的实体类

package com.mybatis03.bean;

/**
 * @author ：jack.zhao
 * @description 教师实体类
 * @date ：2021-10-16 22:55
 */
public class Teacher {

    /* 教师编号 */
    private int teaNo;
    /* 课程编号 */
    private int courseNo;
    /* 教师名称 */
    private String teaName;

    public int getCourseNo() {
        return courseNo;
    }

    public void setCourseNo(int courseNo) {
        this.courseNo = courseNo;
    }

    public int getTeaNo() {
        return teaNo;
    }

    public void setTeaNo(int teaNo) {
        this.teaNo = teaNo;
    }

    public String getTeaName() {
        return teaName;
    }

    public void setTeaName(String teaName) {
        this.teaName = teaName;
    }
}

4.2 教师课程实体类

package com.mybatis03.bean;

/**
 * @author ：jack.zhao
 * @Describe: 教师课程类
 * @date ：2021-10-16 22:55
 */
public class TeacherCourse {

    /* 课程编号 */
    private int courseNo;
    /* 课程名称 */
    private String courseName;

    public int getCourseNo() {
        return courseNo;
    }

    public void setCourseNo(int courseNo) {
        this.courseNo = courseNo;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

}

4.3 教师实体类与课程实体类总的集合类（用于关联数据库表查询结果集）

package com.mybatis03.bean;

/**
 * @author ：jack.zhao
 * @description 此类包含教师和课程属性
 * @date ：2021-10-16 22:55
 */
public class TeacherBusiness extends Teacher {

    public TeacherBusiness(){
        super();
    }



    /* 课程编号 */
    private int courseNo;
    /* 课程名称 */
    private String courseName;

    public int getCourseNo() {
        return courseNo;
    }

    public void setCourseNo(int courseNo) {
        this.courseNo = courseNo;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    @Override
    public String toString() {
        return "TeacherBusiness{" +
                "courseNo=" + courseNo +
                ", courseName='" + courseName +
                ", teacherName='" + this.getTeaName() +
                ", teacherNO='" + this.getTeaNo() + '\'' +
                '}';
    }

}

5、接口类

package com.mybatis03.mapper;

import com.mybatis03.bean.TeacherBusiness;

import java.util.List;

/**
 * @author ：jack.zhao
 * @Describe: 操作mybatis接口
 * @date ：2021-10-16 22:55
 */
public interface TeacherMapper {

    List<TeacherBusiness> queryTeacherBusinessInfoWithCourseNo(int courseNo);
}

6、mapper.xml文件内容

<?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.mybatis03.mapper.TeacherMapper">
    <select id="queryTeacherBusinessInfoWithCourseNo" parameterType="int" resultType="com.mybatis03.bean.TeacherBusiness">
        select s.*,c.* FROM teacher s INNER JOIN teachercourse c
         ON s.courseno = c.courseno
        where s.teano = #{teano}
    </select>
</mapper>

7、测试类

package com.mybatis03.test;

import com.mybatis03.bean.TeacherBusiness;
import com.mybatis03.mapper.TeacherMapper;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.jupiter.api.Test;

import java.io.Reader;
import java.util.List;

/**
 * @author ：jack.zhao
 * @Describe: 测试
 * @date ：2021-10-16 22:55
 */
public class testTeacher01 {

    @Test
    public void queryTeacherBusinessInfoWithCourseNo() throws Exception{
        Reader reader = Resources.getResourceAsReader("mybatis-03.xml");
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);

        SqlSession session = sessionFactory.openSession();
        int courseNo=1002;

        // （jack.zhao）动态代理
        TeacherMapper personMapper = session.getMapper(TeacherMapper.class);
        List<TeacherBusiness> teacherBusinessList = personMapper.queryTeacherBusinessInfoWithCourseNo(courseNo);
        System.out.println("联合查询结果为："+teacherBusinessList);
    }
}

8、执行测试结果