MyBatis基础-11-多对多关联查询

pom.xml

 
  4.0.0
  com.monkey1024
  01mybatis
  0.0.1-SNAPSHOT
  war
  
	  	
		    org.mybatis
		    mybatis
		    3.4.6
		
		
		    mysql
		    mysql-connector-java
		    5.1.46
		
		
		    log4j
		    log4j
		    1.2.17
		
		
		  commons-io
		  commons-io
		  2.6
		
		
		  commons-fileupload
		  commons-fileupload
		  1.3.3
		
		
		   org.hibernate
		   hibernate-validator
		   6.0.9.Final
		
        
            junit
            junit
            3.8.1
            test
        
        
            javax.servlet
            javax.servlet-api
            3.1.0
        
        
            org.springframework
            spring-webmvc
            5.0.4.RELEASE
        

    
    
    	
        01mybatis
        
        	
        		src/main/java
        		
        			**/*.xml
        		
        	
        
        
            
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    
                    1.8
                    1.8
                    UTF-8
                
            
        
    

mybatis.xml

CourseMapper.xml

	
		
		
		
		
			
			
		
	
	
	
		select c.id cid,c.name cname, s.id sid, s.name sname
		from 
			t_course c,
			t_student s,
			t_student_course sc
		where 
			c.id=#{id}
			and s.id=sc.sid
			and c.id=sc.cid
	

db.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/learnmybatis?useSSL=false
jdbc.user=root
jdbc.password=666666

log4j.properties

log4j.rootLogger=debug,console
#log4j.logger.com.monkey1024.dao.StudentDao=debug,concole
#\u63A7\u5236\u53F0\u9644\u52A0\u5668
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern = [%-5p][%d{yyyy-MM--dd HH:mm:ss}]%m%n

Course.java

package com.monkey1024.bean;

import java.util.List;

public class Course {
	private int id;
	private String name;
	private List students;
	
	
	@Override
	public String toString() {
		return "Course [id=" + id + ", name=" + name + ", students=" + students + "]";
	}
	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 List getStudents() {
		return students;
	}
	public void setStudents(List students) {
		this.students = students;
	}
	
}

Student.java

package com.monkey1024.bean;

import java.util.List;

public class Student {
	private int id;
	private String name;
	private int age;
	private double score;
	private List courses;
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", age=" + age + ", score=" + score + ", courses=" + courses
				+ "]";
	}
	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 int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public double getScore() {
		return score;
	}
	public void setScore(double score) {
		this.score = score;
	}
	public List getCourses() {
		return courses;
	}
	public void setCourses(List courses) {
		this.courses = courses;
	}
	
	
}

CourseDao.java

package com.monkey1024.dao;

import com.monkey1024.bean.Course;

public interface CourseDao {
	Course selectCourseStudent(int id);
}

MyBatisUtil.java

package com.monkey1024.util;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

/*
 * DCL鐨勫崟渚嬫ā寮�
 */
public class MyBatisUtil {
	// 鏃犻渶灏嗘瀯閫犳柟娉曠鏈夊寲锛屽洜涓鸿繖閲岄潰鍙淇濊瘉鍒涘缓涓�涓猄qlSessionFactory鐨勫璞�
	// private MyBatisUtil()
	private static volatile SqlSessionFactory sqlSessionFactory;

	public static SqlSession getSqlSession() {
		try {
			if (sqlSessionFactory == null) {
				// 璇诲彇涓婚厤缃枃浠�
				InputStream input = Resources.getResourceAsStream("mybatis.xml");
				synchronized (MyBatisUtil.class) {
					if (sqlSessionFactory == null) {
						sqlSessionFactory = new SqlSessionFactoryBuilder().build(input);
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		//mybatis鑷姩鎻愪氦浜嬪姟
//		return sqlSessionFactory.openSession(true);
		return sqlSessionFactory.openSession();

	}
}

CourseTest01.java

package com.monkey1024.test;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.monkey1024.bean.Course;
import com.monkey1024.dao.CourseDao;
import com.monkey1024.util.MyBatisUtil;

public class CourseTest01 {
	private SqlSession sqlSession;
	private CourseDao courseDao;
	@Before
	public void init(){
		sqlSession = MyBatisUtil.getSqlSession();
		courseDao = sqlSession.getMapper(CourseDao.class);
		
	}
	@After
	public void closeSession(){
		if(sqlSession!=null){
			sqlSession.close();
		}
	}
	
	@Test
	public void selectCourseStudent(){
		Course course = courseDao.selectCourseStudent(1001);
		System.out.println(course);
	}
	
}