使用注解开发

参考视频：【狂神说Java】Mybatis最新完整教程IDEA版通俗易懂点击观看

文章目录

使用注解开发
Mybatis详细的执行流程
事务自动提交
@Param()注解
[#{}与 ${}的区别](#{}与$ {}的区别)
Lombok的使用

使用注解开发

1、注解在接口上实现

java 复制代码

package com.findx.dao;

import com.findx.pojo.User;
import org.apache.ibatis.annotations.*;

import java.util.List;
import java.util.Map;

public interface UserMapper {
    //查询所有用户
    @Select("select * from user")
    List<User> getUsers();
    //根据id查询用户
    @Select("select * from user where id = #{id}")
    User getUserById(@Param("id") int id);
    //删除
    @Delete("delete from user where id = #{uid}")
    int deleteUser(@Param("uid") int id);
    //添加
    @Insert("insert into user (id, name, pwd) values (#{id}, #{name}, #{pwd})")
    int addUser(User user);
    //修改
    @Update("update user set name = #{name}, pwd = #{pwd} where id = #{id}")
    int updateUser(User user);
}

2、在配置文件中绑定接口

3、测试使用

java 复制代码

package com.findx.dao;


import com.findx.pojo.User;
import com.findx.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserMapperTest {
    @Test
    //getUsers
    public void getUsers() {
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> users = mapper.getUsers();
        for (User user : users) {
            System.out.println(user);
        }
        sqlSession.close();
    }
    @Test
    //getUserById
    public void getUserById() {
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = mapper.getUserById(1);
        System.out.println(user);
        sqlSession.close();
    }
    @Test
    //addUser
    public void addUser() {
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        int res = mapper.addUser(new User(11, "findx", "123456"));
        if (res > 0) {
            System.out.println("插入成功");
        }
        //sqlSession.commit();设置为true之后就不需要手动提交事务了
        sqlSession.close();
    }
    @Test
    //updateUser
    public void updateUser() {
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        int res = mapper.updateUser(new User(5, "f111", "123456"));
        if (res > 0) {
            System.out.println("更新成功");
        }
        sqlSession.close();
    }
    @Test
    //deleteUser
    public void deleteUser() {
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        int res = mapper.deleteUser(11);
        if (res > 0) {
            System.out.println("删除成功");
        }
        sqlSession.close();
    }
}