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、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);
}
}
6、执行测试结果