mybaits——动态代理方式的增删改查（又称mybaits接口开发）

原则：约定优于配置，配置优于硬编码

目的：根绝约定直接找到sql语句，而不是通过mapper.xml的包名.类名+的id值定位sql语句

步骤：

1、建一个接口（在mybaits中，是没有接口实现类的）

     在接口中，方法名和mapper.xml标签中的id值保持一致；

    方法的输入参数和mapper.xml文件标签的parameterType类型一致(如果没有parameterType，则说明该方法没有输入参数);

    方法的输出参数和mapper.xml标签中的resultType类型保持一致；

除了以上的约定，要实现接口中的方法和mapper.xml中sql标签一一对应，还需一下两点：

a、 namespace的值，就是接口的全类名（接口  ----mapper.xml  意义对应;根据接口名找到mapper.xml文件）

b、根据接口的方法名找到mapper.xml文件中的sql标签

StudentMapper.java接口

public interface StudentMapper {
	/*约定的原则：
	 * 1、方法名和mapper.xml文件中标签的id值相同
	 * 2、方法的输入参数和mapper.xml文件标签的parameterType类型一致(如果没有parameterType，则说明该方法没有输入参数)
	 * 3、方法的返回值和mapper.xml文件标签的resultType类型一致*/
	 
	//增加
	void addStudent(Student student);
	//修改
	void updateStudentByStuno(Student student);
	//删除
	void deleteStudentByStuno(int stuno);
	//查询全部
	List<Student> queryAllStudents();
	
}

studengMapper.xml

<insert id="addStudentWithConverter" parameterType="com.maven.myBaits.two.Student">
    		insert into student (stuno,stuname,stuage,graname,stusex) values(#{stuNo},#{stuName},#{stuAge},#{graName},#{stuSex,javaType=boolean,jdbcType=INTEGER})
    </insert>
    
    
  
    <update id="updateStudentByStuno" parameterType="com.maven.myBaits.two.Student">
    update student set stuname=#{stuName},stuage=#{stuAge},graname=#{graName},stusex=#{stuSex} where stuno=#{stuNo}
    </update>
    
    <delete id="deleteStudentByStuno" parameterType="int">
    	delete from student where stuno=#{stuno}
    </delete>
    
    <select id="queryAllStudents" resultType="com.maven.myBaits.two.Student">
    	select * from student
    </select>

Test.java

//查询全部学生
		public static void queryAllStudents() throws IOException{
			
			//加载mybaits配置文件
			Reader reader=Resources.getResourceAsReader("conf.xml");
			
			SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader);
			SqlSession session=sessionFactory.openSession();
			
			StudentMapper studentMapper=session.getMapper(StudentMapper.class);
			List<Student> students=studentMapper.queryAllStudents();
			
			System.out.println(students);
			session.close();

		}
		//增加学生
		public static void addStudent() throws IOException{
			
			//加载mybaits配置文件
			Reader reader=Resources.getResourceAsReader("conf.xml");
			
			SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader);
			SqlSession session=sessionFactory.openSession();
			
			Student student=new Student(47,"ss",25,"s1",true);
			
			StudentMapper studentMapper=session.getMapper(StudentMapper.class);
			studentMapper.addStudent(student);
			
			//int count=session.insert(statement,student);//指定执行得sql；student是参数
			session.commit();//提交事物
			System.out.println("增加成功");
			session.close();

		}
		//删除学生
		public static void deleteStudentByStuno() throws IOException{
			
			//加载mybaits配置文件
			Reader reader=Resources.getResourceAsReader("conf.xml");
			
			SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader);
			
			SqlSession session=sessionFactory.openSession();
			
			StudentMapper studentMapper=session.getMapper(StudentMapper.class);
			studentMapper.deleteStudentByStuno(3);	
			//int count=session.delete(statement,123);
			
			session.commit();//提交事物
		    System.out.println("删除成功");
			session.close();
		}
		
		//修改学生
		public static void updateStudentByStuno() throws IOException{
			
			//加载mybaits配置文件
			Reader reader=Resources.getResourceAsReader("conf.xml");
			
			SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(reader);
			
			SqlSession session=sessionFactory.openSession();
			
			StudentMapper studentMapper=session.getMapper(StudentMapper.class);
			
			//修改的参数
			Student student = new Student();
			//修改哪个人,where stuno=1
			student.setStuNo(234);
			//修改成什么样子
			student.setStuName("lxs");
			student.setStuAge(44);
			student.setGraName("s2");
			//执行session
			//int count=session.update(statement,student);
			//提交事务
			
			studentMapper.updateStudentByStuno(student);
			
			session.commit();
			System.out.println("修改成功");
			session.close();
		}

	public static void main(String[] args) throws IOException{
		// TODO Auto-generated method stub
		//queryStudentByStuno();
		//addStudent();
		//queryAllStudents();
		//deleteStudentByStuno();
		//updateStudentByStuno();
		//queryAllStudents();
		
		queryStudentByStunoWithConverter();
		//addStudent();
	}

 

session.getMapper()——动态代理方式

调用接口中的方法定位sql语句