注解

将id：8 name：小A age：54修改 name：大A age：44

UserMapper.java

package com.ij34.model;

import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

public interface UserMapper {
    @Select("select * from users where id=#{id}")
  public User selectUser(int id);
    @Update("update users set name=#{name},age=#{age} where id=#{id}")
  public void updateUser(User user);
}

Test.java

package com.ij34.bean;

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;

import com.ij34.model.User;
import com.ij34.model.UserMapper;
public class Test {
public static void main(String[] args) throws IOException {
    String resource ="com/ij34/mybatis/mybatis-config.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
   SqlSession session=sqlSessionFactory.openSession();
   try {
//       List<User> users=session.selectList("com.ij34.mybatis.UserMapper.selectUser"); 
           UserMapper mapper=session.getMapper(UserMapper.class); 
        User user= mapper.selectUser(8);
        user.setAge(44);
        user.setName("大A");
        mapper.updateUser(user);
        session.commit();
        System.out.println(user);
} finally {
    // TODO: handle finally clause
   session.close();
}
}
}

结果

XML

UserMapper.xml

<?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.ij34.mybatis.UserMapper">
  <select id="selectUser" parameterType="int" resultType="com.ij34.model.User">
    select * from users where id=#{id};
  </select>
    <update id="updateUser" keyProperty="id">
    update users set name=#{name},age=#{age} where id=#{id}
  </update>
  </mapper>

Test.java

package com.ij34.bean;

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;

import com.ij34.model.User;

public class Test {
public static void main(String[] args) throws IOException {
    String resource ="com/ij34/mybatis/mybatis-config.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
   SqlSession session=sqlSessionFactory.openSession();
   try {
       User user=session.selectOne("com.ij34.mybatis.UserMapper.selectUser", 8); //选择
       user.setName("小小A");
       user.setAge(24);
       session.update("com.ij34.mybatis.UserMapper.updateUser", user);    // 更改
       session.commit();
       System.out.println(user);
} finally {
    // TODO: handle finally clause
   session.close();
}
}
}