MyBatis学习2--完成简单的增、删、改、查操作（转）

使用MyBatis进行数据库增删改查的操作是很简单的，主要在配置文件中写好相应的SQL语句，然后在程序中进行调用即可。具体代码如下：

一、映射配置文件

<?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.mapper.UserMapper">
  <select id="selectUser" parameterType="String" resultType="com.dto.UserDto">
    select * from user where username = #{username}
  </select>
  <select id="selectAllUser" resultType="com.dto.UserDto">
    select * from user
  </select>
  <insert id="insertUser" parameterType="com.dto.UserDto">
      insert into user(username,password,address,age,sex)
      values (#{username},#{password},#{address},#{age},#{sex})
  </insert>
  <update id="updateUser" parameterType="com.dto.UserDto">
      update user set password=#{password},address=#{address},age=#{age},sex=#{sex}
      where username=#{username}
  </update>
  <delete id="deleteUser" parameterType="String">
      delete from user where username=#{username}
  </delete>
  <delete id="deleteAllUser">
      delete from user
  </delete>
</mapper>

二、测试类

package com.test;

import java.io.InputStream;
import java.util.List;

import org.apache.ibatis.binding.MapperRegistry;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import com.dto.UserDto;
import com.mapper.UserMapper;

public class UserTest{
    SqlSessionFactory sqlSessionFactory = null;

    @Before
    public void setUp() throws Exception {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Test
    public void seleteXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            UserDto userDto = (UserDto) session.selectOne("com.mapper.UserMapper.selectUser", "test");
            System.out.println(userDto.getUsername()+" "+userDto.getPassword()+" "+userDto.getAddress()+" "+userDto.getAge()+" "+userDto.getSex());
        } finally {
            session.close();
        }
    }
    @Test
    public void seleteAllXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            List<UserDto> list = session.selectList("com.mapper.UserMapper.selectAllUser");
            for(UserDto userDto : list){
                System.out.println(userDto.getUsername()+" "+userDto.getPassword()+" "+userDto.getAddress()+" "+userDto.getAge()+" "+userDto.getSex());
            }
        } finally {
            session.close();
        }
    }

    @Test
    public void seleteAnnotaionTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            UserMapper userMapper = session.getMapper(UserMapper.class);
            UserDto userDto = userMapper.seleteUser("test");
            System.out.println(userDto.getUsername()+" "+userDto.getPassword()+" "+userDto.getAddress()+" "+userDto.getAge()+" "+userDto.getSex());
        } finally {
            session.close();
        }
    }

    @Test
    public void insertXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            UserDto userDto = new UserDto();
            userDto.setUsername("test");
            userDto.setPassword("test");
            userDto.setAddress("测试地址......");
            userDto.setAge("30");
            userDto.setSex("男");
            int res = session.insert("com.mapper.UserMapper.insertUser", userDto);
            session.commit();
            System.out.println("res = " + res);
        } finally {
            session.close();
        }
    }
    @Test
    public void updateXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            UserDto userDto = new UserDto();
            userDto.setUsername("test");
            userDto.setPassword("111111");
            userDto.setAddress("地址");
            userDto.setAge("33");
            userDto.setSex("女");
            int res = session.update("com.mapper.UserMapper.updateUser", userDto);
            session.commit();
            System.out.println("res = " + res);
        } finally {
            session.close();
        }
    }
    @Test
    public void deleteXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            int res = session.delete("com.mapper.UserMapper.deleteUser", "test");
            session.commit();
            System.out.println("res = " + res);
        } finally {
            session.close();
        }
    }
    @Test
    public void deleteAllXMLTest() {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            int res = session.delete("com.mapper.UserMapper.deleteAllUser");
            session.commit();
            System.out.println("res = " + res);
        } finally {
            session.close();
        }
    }
}

注意：在更新操作完成之后需要调用session.commit()方法，不然数据不会更新到数据库中。