MyBatis基于XML的增删改查

在MyBatis入门案例中，实现了查询操作，这篇文章使用XML方式实现增删改查，这里贴出关键部分。

1. 工程目录结构
   
2. UserDao

public interface UserDao {

    List<User> getUserList();

    User getUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);
}

3. 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.dao.UserDao">

    <select id="getUserList" resultType="com.pojo.User">
        select * from user
    </select>

    <select id="getUserById" resultType="com.pojo.User" parameterType="int">
        select * from user where id = #{id}
    </select>

    <insert id="addUser" parameterType="com.pojo.User">
        insert into user (name,password) values (#{name},#{password})
    </insert>

    <update id="updateUser" parameterType="com.pojo.User">
        update user set name=#{name},password=#{password} where id=#{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id = #{id}
    </delete>
</mapper>

4. UserDaoTest

public class UserDaoTest {

    @Test
    public void test(){
        //第一步：获取SqlSession对象
        SqlSession sqlSession= MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserDao userDao=sqlSession.getMapper(UserDao.class);
        List<User> userList=userDao.getUserList();
        for(User user : userList){
            System.out.println(user);
        }
        //关闭SqlSession
        sqlSession.close();
    }

    @Test
    public void getUserById(){
        //第一步：获取SqlSession对象
        SqlSession sqlSession= MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserDao userDao=sqlSession.getMapper(UserDao.class);
        User user=userDao.getUserById(1);
        System.out.println(user);
        sqlSession.close();
    }

    //增删改需要提交事务
    @Test
    public void addUser(){
        //第一步：获取SqlSession对象
        SqlSession sqlSession= MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserDao userDao=sqlSession.getMapper(UserDao.class);
        User user=new User();
        user.setName("张三");
        user.setPassword("123");
        int m=userDao.addUser(user);
        if(m>0){
            System.out.println("插入成功");
        }
        //提交事务，不提交会插入失败
        sqlSession.commit();
        sqlSession.close();
    }

    //增删改需要提交事务
    @Test
    public void updateUser(){
        //第一步：获取SqlSession对象
        SqlSession sqlSession= MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserDao userDao=sqlSession.getMapper(UserDao.class);
        User user=new User();
        user.setId(6);
        user.setName("张三");
        user.setPassword("123123");
        int m=userDao.updateUser(user);
        if(m>0){
            System.out.println("修改成功");
        }
        //提交事务，不提交会更新失败
        sqlSession.commit();
        sqlSession.close();
    }

    //增删改需要提交事务
    @Test
    public void deleteUser(){
        //第一步：获取SqlSession对象
        SqlSession sqlSession= MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserDao userDao=sqlSession.getMapper(UserDao.class);
        int m=userDao.deleteUser(6);
        if(m>0){
            System.out.println("删除成功");
        }
        //提交事务，不提交会删除失败
        sqlSession.commit();
        sqlSession.close();
    }
}